I understand this has been asked for multiple times, but I am really stuck here and if it is fairly easy, please help me.
I have a sample java program and a jar file.
Here is what is inside of the java program (WriterSample.java).
// (c) Copyright 2014. TIBCO Software Inc. All rights reserved.
package com.spotfire.samples;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Date;
import java.util.Random;
import com.spotfire.sbdf.BinaryWriter;
import com.spotfire.sbdf.ColumnMetadata;
import com.spotfire.sbdf.FileHeader;
import com.spotfire.sbdf.TableMetadata;
import com.spotfire.sbdf.TableMetadataBuilder;
import com.spotfire.sbdf.TableWriter;
import com.spotfire.sbdf.ValueType;
/**
* This example is a simple command line tool that writes a simple SBDF file
* with random data.
*/
public class WriterSample {
public static void main(String[] args) throws IOException {
// The command line application requires one argument which is supposed to be
// the name of the SBDF file to write.
if (args.length != 1)
{
System.out.println("Syntax: WriterSample output.sbdf");
return;
}
String outputFile = args[0];
// First we just open the file as usual and then we need to wrap the stream
// in a binary writer.
OutputStream outputStream = new FileOutputStream(outputFile);
BinaryWriter writer = new BinaryWriter(outputStream);
// When writing an SBDF file you first need to write the file header.
FileHeader.writeCurrentVersion(writer);
// The second part of the SBDF file is the metadata, in order to create
// the table metadata we need to use the builder class.
TableMetadataBuilder tableMetadataBuilder = new TableMetadataBuilder();
// The table can have metadata properties defined. Here we add a custom
// property indicating the producer of the file. This will be imported as
// a table property in Spotfire.
tableMetadataBuilder.addProperty("GeneratedBy", "WriterSample.exe");
// All columns in the table needs to be defined and added to the metadata builder,
// the required information is the name of the column and the data type.
ColumnMetadata col1 = new ColumnMetadata("Category", ValueType.STRING);
tableMetadataBuilder.addColumn(col1);
// Similar to tables, columns can also have metadata properties defined. Here
// we add another custom property. This will be imported as a column property
// in Spotfire.
col1.addProperty("SampleProperty", "col1");
ColumnMetadata col2 = new ColumnMetadata("Value", ValueType.DOUBLE);
tableMetadataBuilder.addColumn(col2);
col2.addProperty("SampleProperty", "col2");
ColumnMetadata col3 = new ColumnMetadata("TimeStamp", ValueType.DATETIME);
tableMetadataBuilder.addColumn(col3);
col3.addProperty("SampleProperty", "col3");
// We need to call the build function in order to get an object that we can
// write to the file.
TableMetadata tableMetadata = tableMetadataBuilder.build();
tableMetadata.write(writer);
int rowCount = 10000;
Random random = new Random();
// Now that we have written all the metadata we can start writing the actual data.
// Here we use a TableWriter to write the data, remember to close the table writer
// otherwise you will not generate a correct SBDF file.
TableWriter tableWriter = new TableWriter(writer, tableMetadata);
for (int i = 0; i < rowCount; ++i) {
// You need to perform one addValue call for each column, for each row in the
// same order as you added the columns to the table metadata object.
// In this example we just generate some random values of the appropriate types.
// Here we write the first string column.
String[] col1Values = new String[] {"A", "B", "C", "D", "E"};
tableWriter.addValue(col1Values[random.nextInt(5)]);
// Next we write the second double column.
double doubleValue = random.nextDouble();
if (doubleValue < 0.5) {
// Note that if you want to write a null value you shouldn't send null to
// addValue, instead you should use theInvalidValue property of the columns
// ValueType.
tableWriter.addValue(ValueType.DOUBLE.getInvalidValue());
} else {
tableWriter.addValue(random.nextDouble());
}
// And finally the third date time column.
tableWriter.addValue(new Date());
}
// Finally we need to close the file and write the end of table marker.
tableWriter.writeEndOfTable();
writer.close();
outputStream.close();
System.out.print("Wrote file: ");
System.out.println(outputFile);
}
}
The jar file is sbdf.jar, which is in the same directory as the java file.
I can now compile with:
javac -cp "sbdf.jar" WriterSample.java
This will generate a WriterSample.class file.
The problem is that when I try to execute the program by
java -cp .:./sbdf.jar WriterSample
I got an error message:
Error: Could not find or load main class WriterSample
What should I do? Thanks!
You should use the fully qualified name of the WriterSample, which is com.spotfire.samples.WriterSample and the correct java command is:
java -cp .:././sbdf.jar com.spotfire.samples.WriterSample
Related
I've been reading the H2O documentation for a while, and I haven't found a clear example of how to load model trained and saved using the Python API. I was following the next example.
import h2o
from h2o.estimators.naive_bayes import H2ONaiveBayesEstimator
model = H2ONaiveBayesEstimator()
h2o_df = h2o.import_file("http://s3.amazonaws.com/h2o-public-test-data/smalldata/airlines/allyears2k_headers.zip")
model.train(y = "IsDepDelayed", x = ["Year", "Origin"],
training_frame = h2o_df,
family = "binomial",
lambda_search = True,
max_active_predictors = 10)
h2o.save_model(model, path=models)
But if you check the official documentation it states that you have to download the model as a POJO from the flow UI. Is it the only way? or, may I achieve the same result via python? Just for information, I show the doc's example below. I need some guidance.
import java.io.*;
import hex.genmodel.easy.RowData;
import hex.genmodel.easy.EasyPredictModelWrapper;
import hex.genmodel.easy.prediction.*;
public class main {
private static String modelClassName = "gbm_pojo_test";
public static void main(String[] args) throws Exception {
hex.genmodel.GenModel rawModel;
rawModel = (hex.genmodel.GenModel) Class.forName(modelClassName).newInstance();
EasyPredictModelWrapper model = new EasyPredictModelWrapper(rawModel);
//
// By default, unknown categorical levels throw PredictUnknownCategoricalLevelException.
// Optionally configure the wrapper to treat unknown categorical levels as N/A instead:
//
// EasyPredictModelWrapper model = new EasyPredictModelWrapper(
// new EasyPredictModelWrapper.Config()
// .setModel(rawModel)
// .setConvertUnknownCategoricalLevelsToNa(true));
RowData row = new RowData();
row.put("Year", "1987");
row.put("Month", "10");
row.put("DayofMonth", "14");
row.put("DayOfWeek", "3");
row.put("CRSDepTime", "730");
row.put("UniqueCarrier", "PS");
row.put("Origin", "SAN");
row.put("Dest", "SFO");
BinomialModelPrediction p = model.predictBinomial(row);
System.out.println("Label (aka prediction) is flight departure delayed: " + p.label);
System.out.print("Class probabilities: ");
for (int i = 0; i < p.classProbabilities.length; i++) {
if (i > 0) {
System.out.print(",");
}
System.out.print(p.classProbabilities[i]);
}
System.out.println("");
}
}
h2o.save_model will save the binary model to the provided file system, however, looking at the Java application above it seems you want to use model into a Java based scoring application.
Because of that you should be using h2o.download_pojo API to save the model to local file system along with genmodel jar file. The API is documented as below:
download_pojo(model, path=u'', get_jar=True)
Download the POJO for this model to the directory specified by the path; if the path is "", then dump to screen.
:param model: the model whose scoring POJO should be retrieved.
:param path: an absolute path to the directory where POJO should be saved.
:param get_jar: retrieve the h2o-genmodel.jar also.
Once you have download POJO, you can use the above sample application to perform the scoring and make sure the POJO class name and the "modelClassName" are same along with model type.
I am using Eclipse 4.5.1 Mars and the Data Tools Project is already integrated in this distribution. I am trying to use the SQL Query Parser of the Data Tools Project to parse a SQL-file. I created a new Java project, a package and a class and I used the code example given here:
http://dev.eclipse.org/mhonarc/lists/dtp-sqldevtools-dev/msg00074.html
But I have trouble to resolve the required classes to use the parser. E.g. at the very beginning of the code you find this statement:
SQLQueryParserManager parserManager = SQLQueryParserManagerProvider
SQLQueryParserManager shows an error and asks to "Import 'SQLQueryParserManager ' (org.eclipse.datatools.sqltools.parsers.sql.query)" - which I do. At the import-statement section at the top of the java file "import org.eclipse.datatools.sqltools.parsers.sql.query.SQLQueryParserManager;" is the relevant reference. However, it keep on telling me that 'The import org.eclipse' can not be resolved.
I do not know anymore how to solve it. I tried to download the DTP and copied the plugins in the the plugin Folder of Mars but there was no change either.
Here is the .java-File that I try to run. It is pretty simple but still the required classes can not be resolved for some reasons. The classes should be part of eclipse Mars imo. I tried different Eclipse downloads and for all its the same. Please help
// imports needed
import java.util.Iterator;
import java.util.List;
import org.eclipse.datatools.sqltools.parsers.sql.query.src.org.eclipse.datatools.sqltools.parsers.sql.query.SQLQueryParseResult;
import org.eclipse.datatools.sqltools.parsers.sql.query.src.org.eclipse.datatools.sqltools.parsers.sql.query.SQLQueryParserManager;
import org.eclipse.datatools.sqltools.parsers.sql.query.src.org.eclipse.datatools.sqltools.parsers.sql.query.SQLQueryParserManagerProvider;
import org.eclipse.datatools.sqltools.parsers.sql.src.org.eclipse.datatools.sqltools.parsers.sql.SQLParseErrorInfo;
import org.eclipse.datatools.sqltools.parsers.sql.src.org.eclipse.datatools.sqltools.parsers.sql.SQLParserException;
import org.eclipse.datatools.sqltools.parsers.sql.src.org.eclipse.datatools.sqltools.parsers.sql.SQLParserInternalException;
class LPGParserExample {
public static void main(String args[]) {
try {
// Create an instance the Parser Manager
// SQLQueryParserManagerProvider.getInstance().getParserManager
// returns the best compliant SQLQueryParserManager
// supporting the SQL dialect of the database described by the given
// database product information. In the code below null is passed
// for both the database and version
// in which case a generic parser is returned
SQLQueryParserManager parserManager = SQLQueryParserManagerProvider
.getInstance().getParserManager(null, null);
// Sample query
String sql = "SELECT * FROM TABLE1";
// Parse
SQLQueryParseResult parseResult = parserManager.parseQuery(sql);
// Get the Query Model object from the result
QueryStatement resultObject = parseResult.getQueryStatement();
// Get the SQL text
String parsedSQL = resultObject.getSQL();
System.out.println(parsedSQL);
} catch (SQLParserException spe) {
// handle the syntax error
System.out.println(spe.getMessage());
List syntacticErrors = spe.getErrorInfoList();
Iterator itr = syntacticErrors.iterator();
while (itr.hasNext()) {
SQLParseErrorInfo errorInfo = (SQLParseErrorInfo) itr.next();
// Example usage of the SQLParseErrorInfo object
// the error message
String errorMessage = errorInfo.getParserErrorMessage();
// the line numbers of error
int errorLine = errorInfo.getLineNumberStart();
int errorColumn = errorInfo.getColumnNumberStart();
}
} catch (SQLParserInternalException spie) {
// handle the exception
System.out.println(spie.getMessage());
}
}
}
I'm trying to pass a .arff file to LinearRegression object and while doing so it gives me this exception Cannot handle multi-valued nominal class!.
What actually happening is i'm performing Attribute selection using CFSSubsetEval evaluater and search as GreedyStepwise after doing so, passing those attributes to LinearRegression as follows
LinearRegression rl=new LinearRegression(); rl.buildClassifier(data);
data is the Instance object which has the data from .arff file which previously converted to nominal values using weka only. Am i doing anything wrong here? I was trying to search for this error on google but couldn't find one.
Code
package com.attribute;
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.Random;
import weka.attributeSelection.AttributeSelection;
import weka.attributeSelection.CfsSubsetEval;
import weka.attributeSelection.GreedyStepwise;
import weka.classifiers.Evaluation;
import weka.classifiers.functions.LinearRegression;
import weka.classifiers.meta.AttributeSelectedClassifier;
import weka.classifiers.trees.J48;
import weka.core.Instances;
import weka.core.Utils;
import weka.filters.supervised.attribute.NominalToBinary;
/**
* performs attribute selection using CfsSubsetEval and GreedyStepwise
* (backwards) and trains J48 with that. Needs 3.5.5 or higher to compile.
*
* #author FracPete (fracpete at waikato dot ac dot nz)
*/
public class AttributeSelectionTest2 {
/**
* uses the meta-classifier
*/
protected static void useClassifier(Instances data) throws Exception {
System.out.println("\n1. Meta-classfier");
AttributeSelectedClassifier classifier = new AttributeSelectedClassifier();
CfsSubsetEval eval = new CfsSubsetEval();
GreedyStepwise search = new GreedyStepwise();
search.setSearchBackwards(true);
J48 base = new J48();
classifier.setClassifier(base);
classifier.setEvaluator(eval);
classifier.setSearch(search);
Evaluation evaluation = new Evaluation(data);
evaluation.crossValidateModel(classifier, data, 10, new Random(1));
System.out.println(evaluation.toSummaryString());
}
/**
* uses the low level approach
*/
protected static void useLowLevel(Instances data) throws Exception {
System.out.println("\n3. Low-level");
AttributeSelection attsel = new AttributeSelection();
CfsSubsetEval eval = new CfsSubsetEval();
GreedyStepwise search = new GreedyStepwise();
search.setSearchBackwards(true);
attsel.setEvaluator(eval);
attsel.setSearch(search);
attsel.SelectAttributes(data);
int[] indices = attsel.selectedAttributes();
System.out.println("selected attribute indices (starting with 0):\n"
+ Utils.arrayToString(indices));
useLinearRegression(indices, data);
}
protected static void useLinearRegression(int[] indices, Instances data) throws Exception{
System.out.println("\n 4. Linear-Regression on above selected attributes");
BufferedReader reader = new BufferedReader(new FileReader(
"C:/Entertainement/MS/Fall 2014/spdb/project 4/healthcare.arff"));
Instances data1 = new Instances(reader);
data.setClassIndex(data.numAttributes() - 1);
/*NominalToBinary nb = new NominalToBinary();
for(int i=0;i<=20; i++){
//Still coding left here, create an Instance variable to store the data from 'data' variable for given indices
Instances data_lr=data1.
}*/
LinearRegression rl=new LinearRegression(); //Creating a LinearRegression Object to pass data1
rl.buildClassifier(data1);
}
/**
* takes a dataset as first argument
*
* #param args
* the commandline arguments
* #throws Exception
* if something goes wrong
*/
public static void main(String[] args) throws Exception {
// load data
System.out.println("\n0. Loading data");
BufferedReader reader = new BufferedReader(new FileReader(
"C:/Entertainement/MS/Fall 2014/spdb/project 4/healthcare.arff"));
Instances data = new Instances(reader);
if (data.classIndex() == -1)
data.setClassIndex(data.numAttributes() - 14);
// 1. meta-classifier
useClassifier(data);
// 2. filter
//useFilter(data);
// 3. low-level
useLowLevel(data);
}
}
NOTE : As i have not written code to build an instance variable with 'indices' attributes, i'm (for the sake of program to run) loading data from the same original file.
I don't know how to upload a file for sample data, but it looks something like this. [link] (https://scontent-a-dfw.xx.fbcdn.net/hphotos-xfa1/t31.0-8/p552x414/10496920_756438941076936_8448023649960186530_o.jpg)
Based on your data, it appears that your last attribute is a nominal data type (Contains mostly numbers, but there are some strings as well). LinearRegression will not allow the prediction of nominal classes.
What you could potentially do to ensure that your given dataset works is run it through the Weka Explorer with Linear Regression and see if the desired outcome is generated. Following this, there is a good chance that the data will work correctly in your code.
Hope this Helps!
Here is example of dataset for LinearRegression (source)
#RELATION house
#ATTRIBUTE houseSize NUMERIC
#ATTRIBUTE lotSize NUMERIC
#ATTRIBUTE bedrooms NUMERIC
#ATTRIBUTE granite NUMERIC
#ATTRIBUTE bathroom NUMERIC
#ATTRIBUTE sellingPrice NUMERIC
#DATA
3529,9191,6,0,0,205000
3247,10061,5,1,1,224900
4032,10150,5,0,1,197900
2397,14156,4,1,0,189900
2200,9600,4,0,1,195000
3536,19994,6,1,1,325000
2983,9365,5,0,1,230000
I looked at the included Excel example of the latest version of Java Com Bridge (jacob-1.16) and was a little disappointed because it creates and works on a brand new Excel file.
What I would like to do is having access to an existing Excel file from Java, in this case named 'JACOBWithExcel.xls', but any Excel file should be fine.
The SourceForge example for Excel works fine on my machine, and as I modified it for accessing an existing Excel file I ran into the following issues:
1., I could not get an existing sheet in the workbook, even though I am trying the
same way I got the workbook:
Dispatch sheet = Dispatch.get(workbook, "Worksheets").toDispatch();
Dispatch.call(sheet, "Select", new Object[]{"Sheet2"}).toDispatch();
This code will generate the following exception:
com.jacob.com.ComFailException: Can't map name to dispid: Worksheets
2.; Could not save the workbook:
// Save the open workbook as "C:\jacob-1.16-M1\Test1.xls" file:
Dispatch.call(workbook, "SaveAs", new Variant("C:\\jacob-1.16-M1\\Test1.xls"),new Variant("1"));
This code will generate the following exception:
com.jacob.com.ComFailException: Can't map name to dispid: SaveAs
3.; I don't know how to get started with the following simple but very common Excel operations, as far as Java syntax for Java COM bridge:
(Included here the Excel VBA code that I am trying to implement in Java)
Selecting a single cell:
Range("A4").Select
Copy selected range to clipboard:
Selection.Copy
Select multi-cell range to copy to:
Range("D9:D17").Select
Paste clipboard contents to selection:
ActiveSheet.Paste
Renaming a sheet:
Sheets("Sheet2").Select
Sheets("Sheet2").Name = "MySheet2"
Format cells, example for text:
Selection.NumberFormat = "#"
Delete Rows:
Rows(intI).Select
Selection.Delete Shift:=xlUp
And possibly...
Sort a selection:
Selection.Sort Key1:=Range("A2"), Order1:=xlAscending, Header:=xlGuess, _
OrderCustom:=1, MatchCase:=False, Orientation:=xlTopToBottom
Find the last cell in sheet:
ActiveSheet.Cells(65536, 1).End(xlUp).Select
intLastCellRow = Selection.Row
Thank you for your help.
P.S.:
The full code of the application:
import com.jacob.activeX.ActiveXComponent;
import com.jacob.com.ComThread;
import com.jacob.com.Dispatch;
import com.jacob.com.Variant;
public class TestJACOBWithExcel {
public static void main(String[] args) {
String strInputDoc = "C:\\jacob-1.16-M1\\JACOBWithExcel.xls"; // file to be opened.
ComThread.InitSTA();
ActiveXComponent xl = new ActiveXComponent("Excel.Application"); // Instance of application object created.
try {
// Get Excel application object properties in 2 ways:
System.out.println("version=" + xl.getProperty("Version"));
System.out.println("version=" + Dispatch.get(xl, "Version"));
// Make Excel instance visible:
Dispatch.put(xl, "Visible", new Variant(true));
// Open XLS file, get the workbooks object required for access:
Dispatch workbook = xl.getProperty("Workbooks").toDispatch();
Dispatch.call(workbook, "Open", new Variant(strInputDoc),new Variant("1"));
Dispatch sheet = Dispatch.get(workbook, "Worksheets").toDispatch();
Dispatch.call(sheet, "Select", new Object[]{"Sheet2"}).toDispatch();
// put in a value in cell A22 and place a a formula in cell A23:
Dispatch a22 = Dispatch.invoke(sheet, "Range", Dispatch.Get, new Object[] { "A22" }, new int[1]).toDispatch();
Dispatch a23 = Dispatch.invoke(sheet, "Range", Dispatch.Get, new Object[] { "A23" }, new int[1]).toDispatch();
Dispatch.put(a22, "Value", "123.456");
Dispatch.put(a23, "Formula", "=A22*2");
// Get values from cells A1 and A2
System.out.println("a22 from excel:" + Dispatch.get(a22, "Value"));
System.out.println("a23 from excel:" + Dispatch.get(a23, "Value"));
// Save the open workbook as "C:\jacob-1.16-M1\Test1.xls" file:
Dispatch.call(workbook, "SaveAs", new Variant("C:\\jacob-1.16-M1\\Test1.xls"),new Variant("1"));
// Close the Excel workbook without saving:
Variant saveYesNo = new Variant(false);
Dispatch.call(workbook, "Close", saveYesNo);
} catch (Exception e) {
e.printStackTrace();
} finally {
// Quit Excel:
// xl.invoke("Quit", new Variant[] {});
ComThread.Release();
}
}
}
Hy,
actually i can only answer to your first question right now. I use this code and it's working for *.xltx Template files properly:
File file = new File("pathToOurTemplate");
ActiveXComponent excel = null;
ComThread.InitSTA();
try {
excel = new ActiveXComponent("Excel.Application");
Dispatch excelObject = excel.getObject();
Dispatch workbooks = excel.getProperty("Workbooks").toDispatch();
Dispatch workbook = Dispatch.call(workbooks, "Add", file.getAbsolutePath()).toDispatch();
} catch (...)
//...
Works at least with Office 2010, Java6_u23, Jacob 1.15_M4
Hope this helps for a first shot / this is more what you need than shown in the examples (guess you took a look at those).
Disclaimer: In this answer i will be reffering MS Excel object properties, methods and object types with double quotation to try to avoid some confusion. My answer to this question follows.
Hi,
it is important to understand the hierarchy, that excel API have. And also search what types of methods, properties or events are available on each level of hierarchy. Im going to answer your quetions now.
In question 1 you say you cannot open correct worksheet and thats because you are getting property "Worksheets" on wrong type of object. In your code snippet
Dispatch sheet = Dispatch.get(workbook, "Worksheets").toDispatch();
Dispatch.call(sheet, "Select", new Object[]{"Sheet2"}).toDispatch();
you get property "Worksheets" on object of type "Workbooks", which is incorrect one.
This doc https://msdn.microsoft.com/EN-US/library/office/ff841074.aspx shows, that "Workbooks" doesnt have property "Worksheets". Problem is in how you open concrete "Workbook" object.
Dispatch workbook = xl.getProperty("Workbooks").toDispatch();
Dispatch.call(workbook, "Open", new Variant(strInputDoc),new Variant("1"));
You call method "Open" on "Workbooks" object, which according doc have this method and it opens MS Excel for you. Problem is variable "Dispatch workbook" is still object of type "Workbooks" and not "Workbook", which you wrongly assumed. Correct way is to save return value of your "Open" method call, which gives you concrete "Workbook" object and after that use methods available for that type of object. Exactly following MS docu here https://msdn.microsoft.com/en-us/library/office/ff194819.aspx .
So correct way to open concrete worksheet would be like this:
//get "Workbooks" property from "Application" object
Dispatch workbooks = xl.getProperty("Workbooks").toDispatch();
//call method "Open" with filepath param on "Workbooks" object and save "Workbook" object
Dispatch workbook = Dispatch.call(workbooks, "Open", new Variant(strInputDoc)).toDispatch();
//get "Worksheets" property from "Workbook" object
Dispatch sheets = Dispatch.get(workbook, "Worksheets").toDispatch();
//Call method "Select" on "Worksheets" object with "Sheet2" param
Dispatch.call(sheets, "Select", new Object[]{"Sheet2"}).toDispatch();
//probably again save "Worksheet" object and continue same way
In question 2 is the same problem as in question 1.
//calling method "SaveAs" on "Workbooks" object instead of "Workbook" type
Dispatch.call(workbook, "SaveAs", new Variant("C:\\jacob-1.16-M1\\Test1.xls"),new Variant("1"));
All other questions are just same principle as two before. Get property or call method on correct MS object. Also cannot stress enough, how important MS docu will be for anyone with java-excel comunication.
Will just mention a example, how to get actual values from some MS objects. Lets say you want values inside "Range" object, because getting properties of objects, that require parameters is done a bit differently then normal value property. To do this you need to get to "Worksheet" object first and get "Range" property from that.
//lets say we have already some "Worksheet" object
Dispatch worksheet = ...;
//we want a property "Range" of "Worksheet" object with some macro
Variant range = Dispatch.invoke(worksheet, "Range", Dispatch.Get, new Object[]{"A1:L10"}, new int[1]);
//according to docu, you can specify format in which the value is returned
//im using 12 which is one of XML formats available
//in case no such param is provided default "textTable" format is returned
Variant value = Dispatch.invoke(range.getDispatch(), "Value", Dispatch.Get, new Object[]{12}, new int[1]);
//and get the value from it and you are done with MS Excel-Java communication
String xmlFormat = value.toString();
Worksheet.Range property docu:
msdn.microsoft.com/en-us/library/office/ff836512.aspx
Range.Value docu:
msdn.microsoft.com/en-us/library/office/ff195193.aspx
Im not allowed to post more than 2 links, so im sorry if these links arent working properly.
I am looking for a SQL Library that will parse an SQL statement and return some sort of Object representation of the SQL statement. My main objective is actually to be able to parse the SQL statement and retrieve the list of table names present in the SQL statement (including subqueries, joins and unions).
I am looking for a free library with a license business friendly (e.g. Apache license). I am looking for a library and not for an SQL Grammar. I do not want to build my own parser.
The best I could find so far was JSQLParser, and the example they give is actually pretty close to what I am looking for. However it fails parsing too many good queries (DB2 Database) and I'm hoping to find a more reliable library.
I doubt you'll find anything prewritten that you can just use. The problem is that ISO/ANSI SQL is a very complicated grammar — something like more than 600 production rules IIRC.
Terence Parr's ANTLR parser generator (Java, but can generate parsers in any one of a number of target languages) has several SQL grammars available, including a couple for PL/SQL, one for a SQL Server SELECT statement, one for mySQL, and one for ISO SQL.
No idea how complete/correct/up-to-date they are.
http://www.antlr.org/grammar/list
You needn't reinvent the wheel, there is already such a reliable SQL parser library there, (it's commerical, not free), and this article shows how to retrieve the list of table names present in the SQL statement (including subqueries, joins and unions) that is exactly what you are looking for.
http://www.dpriver.com/blog/list-of-demos-illustrate-how-to-use-general-sql-parser/get-columns-and-tables-in-sql-script/
This SQL parser library supports Oracle, SQL Server, DB2, MySQL, Teradata and ACCESS.
You need the ultra light, ultra fast library to extract table names from SQL (Disclaimer: I am the owner)
Just add the following in your pom
<dependency>
<groupId>com.github.mnadeem</groupId>
<artifactId>sql-table-name-parser</artifactId>
<version>0.0.1</version>
And do the following
new TableNameParser(sql).tables()
For more details, refer the project
Old question, but I think this project contains what you need:
Data Tools Project - SQL Development Tools
Here's the documentation for the SQL Query Parser.
Also, here's a small sample program. I'm no Java programmer so use with care.
package org.lala;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.charset.Charset;
import java.util.Iterator;
import java.util.List;
import org.eclipse.datatools.modelbase.sql.query.QuerySelectStatement;
import org.eclipse.datatools.modelbase.sql.query.QueryStatement;
import org.eclipse.datatools.modelbase.sql.query.TableReference;
import org.eclipse.datatools.modelbase.sql.query.ValueExpressionColumn;
import org.eclipse.datatools.modelbase.sql.query.helper.StatementHelper;
import org.eclipse.datatools.sqltools.parsers.sql.SQLParseErrorInfo;
import org.eclipse.datatools.sqltools.parsers.sql.SQLParserException;
import org.eclipse.datatools.sqltools.parsers.sql.SQLParserInternalException;
import org.eclipse.datatools.sqltools.parsers.sql.query.SQLQueryParseResult;
import org.eclipse.datatools.sqltools.parsers.sql.query.SQLQueryParserManager;
import org.eclipse.datatools.sqltools.parsers.sql.query.SQLQueryParserManagerProvider;
public class SQLTest {
private static String readFile(String path) throws IOException {
FileInputStream stream = new FileInputStream(new File(path));
try {
FileChannel fc = stream.getChannel();
MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0,
fc.size());
/* Instead of using default, pass in a decoder. */
return Charset.defaultCharset().decode(bb).toString();
} finally {
stream.close();
}
}
/**
* #param args
* #throws IOException
*/
public static void main(String[] args) throws IOException {
try {
// Create an instance the Parser Manager
// SQLQueryParserManagerProvider.getInstance().getParserManager
// returns the best compliant SQLQueryParserManager
// supporting the SQL dialect of the database described by the given
// database product information. In the code below null is passed
// for both the database and version
// in which case a generic parser is returned
SQLQueryParserManager parserManager = SQLQueryParserManagerProvider
.getInstance().getParserManager("DB2 UDB", "v9.1");
// Sample query
String sql = readFile("c:\\test.sql");
// Parse
SQLQueryParseResult parseResult = parserManager.parseQuery(sql);
// Get the Query Model object from the result
QueryStatement resultObject = parseResult.getQueryStatement();
// Get the SQL text
String parsedSQL = resultObject.getSQL();
System.out.println(parsedSQL);
// Here we have the SQL code parsed!
QuerySelectStatement querySelect = (QuerySelectStatement) parseResult
.getSQLStatement();
List columnExprList = StatementHelper
.getEffectiveResultColumns(querySelect);
Iterator columnIt = columnExprList.iterator();
while (columnIt.hasNext()) {
ValueExpressionColumn colExpr = (ValueExpressionColumn) columnIt
.next();
// DataType dataType = colExpr.getDataType();
System.out.println("effective result column: "
+ colExpr.getName());// + " with data type: " +
// dataType.getName());
}
List tableList = StatementHelper.getTablesForStatement(resultObject);
// List tableList = StatementHelper.getTablesForStatement(querySelect);
for (Object obj : tableList) {
TableReference t = (TableReference) obj;
System.out.println(t.getName());
}
} catch (SQLParserException spe) {
// handle the syntax error
System.out.println(spe.getMessage());
#SuppressWarnings("unchecked")
List<SQLParseErrorInfo> syntacticErrors = spe.getErrorInfoList();
Iterator<SQLParseErrorInfo> itr = syntacticErrors.iterator();
while (itr.hasNext()) {
SQLParseErrorInfo errorInfo = (SQLParseErrorInfo) itr.next();
// Example usage of the SQLParseErrorInfo object
// the error message
String errorMessage = errorInfo.getParserErrorMessage();
String expectedText = errorInfo.getExpectedText();
String errorSourceText = errorInfo.getErrorSourceText();
// the line numbers of error
int errorLine = errorInfo.getLineNumberStart();
int errorColumn = errorInfo.getColumnNumberStart();
System.err.println("Error in line " + errorLine + ", column "
+ errorColumn + ": " + expectedText + " "
+ errorMessage + " " + errorSourceText);
}
} catch (SQLParserInternalException spie) {
// handle the exception
System.out.println(spie.getMessage());
}
System.exit(0);
}
}