I have the below Stream class that is getting returned from DB:
Stream<Transaction> transctions=transRepository.findByTransctionId();
public class Transaction{
String transctionId;
String accountId;
String transName;
String accountName;
}
Now my Requirement is as below:
Transaction entity has 4 fields. So, from DB all the 4 fields were fetched by Jpa.
But client who needs this data ,he has sent the columnsName in list that he is looking from Transaction model
List<String> columnNames=Arrays.asList("transctionId","accountName")
I have post this data to Kafka.I have to take each Transction from this stream post it to kafka.
But cline is looking for only this 2 fields "transctionId","accountName" should go as part of Transaction in Kafka instead of all 4 fields.
The data should go in form of json to Kafa having below format:
{
"transctionId":"1234",
"accountName" :"test-account"
}
Basically only those fields should go to kafka which they have asked for instead of converting the whole pojo to json and send it.
Is there any way to achieve that?
If you need to invoke a method, but you only have its name, the only way I know is via reflection. I would do it like this:
Stream<Transaction> transctions=transRepository.findByTransctionId();
List<Transaction> outTransactions = new ArrayList<>();
List<String> columnNames = new ArrayList<>();
transactions.forEach(tr -> {
Transaction outTransaction = new Transaction();
columnNames.forEach( col -> {
try {
var getMethod = tr.getClass().getMethod("get" + StringUtils.capitalize(col));
Object value = getMethod.invoke(tr);
String valueStr = value instanceof String ? value.toString() : "";
var setMethod = outTransaction.getClass().getMethod("set" + StringUtils.capitalize(col));
setMethod.invoke(outTransaction, valueStr);
} catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException e) {
e.printStackTrace();
}
});
outTransactions.add(outTransaction);
});
There is a lot of traversing, but with the requirements you have, this is the generic solution I can come up with. Another shortcoming to this solution is the creation of new Transaction objects. Which means that if Transactions are many, memory usage can grow. Maybe this solution can be optimised to take advantage of streaming the transactions from the DB.
Another way to do it is to have different endpoints for each known set of properties that the client sends you. For example:
#GetMapping("/transaction_id_and_name")
List<Transaction> getTransactionsIdAndName() {
... obtain Transactions, return a new list of Transactions, with transaction_id and name ... }
#GetMapping("/transaction_id_and_status")
List<Transaction> getTransactionsNameAndStatus() {...}
I am running data.bat file with the following lines:
Rem Tis batch file will populate tables
cd\program files\Microsoft SQL Server\MSSQL
osql -U sa -P Password -d MyBusiness -i c:\data.sql
The contents of the data.sql file is:
insert Customers
(CustomerID, CompanyName, Phone)
Values('101','Southwinds','19126602729')
There are 8 more similar lines for adding records.
When I run this with start > run > cmd > c:\data.bat, I get this error message:
1>2>3>4>5>....<1 row affected>
Msg 8152, Level 16, State 4, Server SP1001, Line 1
string or binary data would be truncated.
<1 row affected>
<1 row affected>
<1 row affected>
<1 row affected>
<1 row affected>
<1 row affected>
Also, I am a newbie obviously, but what do Level #, and state # mean, and how do I look up error messages such as the one above: 8152?
From #gmmastros's answer
Whenever you see the message....
string or binary data would be truncated
Think to yourself... The field is NOT big enough to hold my data.
Check the table structure for the customers table. I think you'll find that the length of one or more fields is NOT big enough to hold the data you are trying to insert. For example, if the Phone field is a varchar(8) field, and you try to put 11 characters in to it, you will get this error.
I had this issue although data length was shorter than the field length.
It turned out that the problem was having another log table (for audit trail), filled by a trigger on the main table, where the column size also had to be changed.
In one of the INSERT statements you are attempting to insert a too long string into a string (varchar or nvarchar) column.
If it's not obvious which INSERT is the offender by a mere look at the script, you could count the <1 row affected> lines that occur before the error message. The obtained number plus one gives you the statement number. In your case it seems to be the second INSERT that produces the error.
Just want to contribute with additional information: I had the same issue and it was because of the field wasn't big enough for the incoming data and this thread helped me to solve it (the top answer clarifies it all).
BUT it is very important to know what are the possible reasons that may cause it.
In my case i was creating the table with a field like this:
Select '' as Period, * From Transactions Into #NewTable
Therefore the field "Period" had a length of Zero and causing the Insert operations to fail. I changed it to "XXXXXX" that is the length of the incoming data and it now worked properly (because field now had a lentgh of 6).
I hope this help anyone with same issue :)
Some of your data cannot fit into your database column (small). It is not easy to find what is wrong. If you use C# and Linq2Sql, you can list the field which would be truncated:
First create helper class:
public class SqlTruncationExceptionWithDetails : ArgumentOutOfRangeException
{
public SqlTruncationExceptionWithDetails(System.Data.SqlClient.SqlException inner, DataContext context)
: base(inner.Message + " " + GetSqlTruncationExceptionWithDetailsString(context))
{
}
/// <summary>
/// PArt of code from following link
/// http://stackoverflow.com/questions/3666954/string-or-binary-data-would-be-truncated-linq-exception-cant-find-which-fiel
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
static string GetSqlTruncationExceptionWithDetailsString(DataContext context)
{
StringBuilder sb = new StringBuilder();
foreach (object update in context.GetChangeSet().Updates)
{
FindLongStrings(update, sb);
}
foreach (object insert in context.GetChangeSet().Inserts)
{
FindLongStrings(insert, sb);
}
return sb.ToString();
}
public static void FindLongStrings(object testObject, StringBuilder sb)
{
foreach (var propInfo in testObject.GetType().GetProperties())
{
foreach (System.Data.Linq.Mapping.ColumnAttribute attribute in propInfo.GetCustomAttributes(typeof(System.Data.Linq.Mapping.ColumnAttribute), true))
{
if (attribute.DbType.ToLower().Contains("varchar"))
{
string dbType = attribute.DbType.ToLower();
int numberStartIndex = dbType.IndexOf("varchar(") + 8;
int numberEndIndex = dbType.IndexOf(")", numberStartIndex);
string lengthString = dbType.Substring(numberStartIndex, (numberEndIndex - numberStartIndex));
int maxLength = 0;
int.TryParse(lengthString, out maxLength);
string currentValue = (string)propInfo.GetValue(testObject, null);
if (!string.IsNullOrEmpty(currentValue) && maxLength != 0 && currentValue.Length > maxLength)
{
//string is too long
sb.AppendLine(testObject.GetType().Name + "." + propInfo.Name + " " + currentValue + " Max: " + maxLength);
}
}
}
}
}
}
Then prepare the wrapper for SubmitChanges:
public static class DataContextExtensions
{
public static void SubmitChangesWithDetailException(this DataContext dataContext)
{
//http://stackoverflow.com/questions/3666954/string-or-binary-data-would-be-truncated-linq-exception-cant-find-which-fiel
try
{
//this can failed on data truncation
dataContext.SubmitChanges();
}
catch (SqlException sqlException) //when (sqlException.Message == "String or binary data would be truncated.")
{
if (sqlException.Message == "String or binary data would be truncated.") //only for EN windows - if you are running different window language, invoke the sqlException.getMessage on thread with EN culture
throw new SqlTruncationExceptionWithDetails(sqlException, dataContext);
else
throw;
}
}
}
Prepare global exception handler and log truncation details:
protected void Application_Error(object sender, EventArgs e)
{
Exception ex = Server.GetLastError();
string message = ex.Message;
//TODO - log to file
}
Finally use the code:
Datamodel.SubmitChangesWithDetailException();
Another situation in which you can get this error is the following:
I had the same error and the reason was that in an INSERT statement that received data from an UNION, the order of the columns was different from the original table. If you change the order in #table3 to a, b, c, you will fix the error.
select a, b, c into #table1
from #table0
insert into #table1
select a, b, c from #table2
union
select a, c, b from #table3
on sql server you can use SET ANSI_WARNINGS OFF like this:
using (SqlConnection conn = new SqlConnection("Data Source=XRAYGOAT\\SQLEXPRESS;Initial Catalog='Healthy Care';Integrated Security=True"))
{
conn.Open();
using (var trans = conn.BeginTransaction())
{
try
{
using cmd = new SqlCommand("", conn, trans))
{
cmd.CommandText = "SET ANSI_WARNINGS OFF";
cmd.ExecuteNonQuery();
cmd.CommandText = "YOUR INSERT HERE";
cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
cmd.CommandText = "SET ANSI_WARNINGS ON";
cmd.ExecuteNonQuery();
trans.Commit();
}
}
catch (Exception)
{
trans.Rollback();
}
}
conn.Close();
}
I had the same issue. The length of my column was too short.
What you can do is either increase the length or shorten the text you want to put in the database.
Also had this problem occurring on the web application surface.
Eventually found out that the same error message comes from the SQL update statement in the specific table.
Finally then figured out that the column definition in the relating history table(s) did not map the original table column length of nvarchar types in some specific cases.
I had the same problem, even after increasing the size of the problematic columns in the table.
tl;dr: The length of the matching columns in corresponding Table Types may also need to be increased.
In my case, the error was coming from the Data Export service in Microsoft Dynamics CRM, which allows CRM data to be synced to an SQL Server DB or Azure SQL DB.
After a lengthy investigation, I concluded that the Data Export service must be using Table-Valued Parameters:
You can use table-valued parameters to send multiple rows of data to a Transact-SQL statement or a routine, such as a stored procedure or function, without creating a temporary table or many parameters.
As you can see in the documentation above, Table Types are used to create the data ingestion procedure:
CREATE TYPE LocationTableType AS TABLE (...);
CREATE PROCEDURE dbo.usp_InsertProductionLocation
#TVP LocationTableType READONLY
Unfortunately, there is no way to alter a Table Type, so it has to be dropped & recreated entirely. Since my table has over 300 fields (😱), I created a query to facilitate the creation of the corresponding Table Type based on the table's columns definition (just replace [table_name] with your table's name):
SELECT 'CREATE TYPE [table_name]Type AS TABLE (' + STRING_AGG(CAST(field AS VARCHAR(max)), ',' + CHAR(10)) + ');' AS create_type
FROM (
SELECT TOP 5000 COLUMN_NAME + ' ' + DATA_TYPE
+ IIF(CHARACTER_MAXIMUM_LENGTH IS NULL, '', CONCAT('(', IIF(CHARACTER_MAXIMUM_LENGTH = -1, 'max', CONCAT(CHARACTER_MAXIMUM_LENGTH,'')), ')'))
+ IIF(DATA_TYPE = 'decimal', CONCAT('(', NUMERIC_PRECISION, ',', NUMERIC_SCALE, ')'), '')
AS field
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = '[table_name]'
ORDER BY ORDINAL_POSITION) AS T;
After updating the Table Type, the Data Export service started functioning properly once again! :)
When I tried to execute my stored procedure I had the same problem because the size of the column that I need to add some data is shorter than the data I want to add.
You can increase the size of the column data type or reduce the length of your data.
A 2016/2017 update will show you the bad value and column.
A new trace flag will swap the old error for a new 2628 error and will print out the column and offending value. Traceflag 460 is available in the latest cumulative update for 2016 and 2017:
https://support.microsoft.com/en-sg/help/4468101/optional-replacement-for-string-or-binary-data-would-be-truncated
Just make sure that after you've installed the CU that you enable the trace flag, either globally/permanently on the server:
...or with DBCC TRACEON:
https://learn.microsoft.com/en-us/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql?view=sql-server-ver15
Another situation, in which this error may occur is in
SQL Server Management Studio. If you have "text" or "ntext" fields in your table,
no matter what kind of field you are updating (for example bit or integer).
Seems that the Studio does not load entire "ntext" fields and also updates ALL fields instead of the modified one.
To solve the problem, exclude "text" or "ntext" fields from the query in Management Studio
This Error Comes only When any of your field length is greater than the field length specified in sql server database table structure.
To overcome this issue you have to reduce the length of the field Value .
Or to increase the length of database table field .
If someone is encountering this error in a C# application, I have created a simple way of finding offending fields by:
Getting the column width of all the columns of a table where we're trying to make this insert/ update. (I'm getting this info directly from the database.)
Comparing the column widths to the width of the values we're trying to insert/ update.
Assumptions/ Limitations:
The column names of the table in the database match with the C# entity fields. For eg: If you have a column like this in database:
You need to have your Entity with the same column name:
public class SomeTable
{
// Other fields
public string SourceData { get; set; }
}
You're inserting/ updating 1 entity at a time. It'll be clearer in the demo code below. (If you're doing bulk inserts/ updates, you might want to either modify it or use some other solution.)
Step 1:
Get the column width of all the columns directly from the database:
// For this, I took help from Microsoft docs website:
// https://learn.microsoft.com/en-us/dotnet/api/system.data.sqlclient.sqlconnection.getschema?view=netframework-4.7.2#System_Data_SqlClient_SqlConnection_GetSchema_System_String_System_String___
private static Dictionary<string, int> GetColumnSizesOfTableFromDatabase(string tableName, string connectionString)
{
var columnSizes = new Dictionary<string, int>();
using (var connection = new SqlConnection(connectionString))
{
// Connect to the database then retrieve the schema information.
connection.Open();
// You can specify the Catalog, Schema, Table Name, Column Name to get the specified column(s).
// You can use four restrictions for Column, so you should create a 4 members array.
String[] columnRestrictions = new String[4];
// For the array, 0-member represents Catalog; 1-member represents Schema;
// 2-member represents Table Name; 3-member represents Column Name.
// Now we specify the Table_Name and Column_Name of the columns what we want to get schema information.
columnRestrictions[2] = tableName;
DataTable allColumnsSchemaTable = connection.GetSchema("Columns", columnRestrictions);
foreach (DataRow row in allColumnsSchemaTable.Rows)
{
var columnName = row.Field<string>("COLUMN_NAME");
//var dataType = row.Field<string>("DATA_TYPE");
var characterMaxLength = row.Field<int?>("CHARACTER_MAXIMUM_LENGTH");
// I'm only capturing columns whose Datatype is "varchar" or "char", i.e. their CHARACTER_MAXIMUM_LENGTH won't be null.
if(characterMaxLength != null)
{
columnSizes.Add(columnName, characterMaxLength.Value);
}
}
connection.Close();
}
return columnSizes;
}
Step 2:
Compare the column widths with the width of the values we're trying to insert/ update:
public static Dictionary<string, string> FindLongBinaryOrStringFields<T>(T entity, string connectionString)
{
var tableName = typeof(T).Name;
Dictionary<string, string> longFields = new Dictionary<string, string>();
var objectProperties = GetProperties(entity);
//var fieldNames = objectProperties.Select(p => p.Name).ToList();
var actualDatabaseColumnSizes = GetColumnSizesOfTableFromDatabase(tableName, connectionString);
foreach (var dbColumn in actualDatabaseColumnSizes)
{
var maxLengthOfThisColumn = dbColumn.Value;
var currentValueOfThisField = objectProperties.Where(f => f.Name == dbColumn.Key).First()?.GetValue(entity, null)?.ToString();
if (!string.IsNullOrEmpty(currentValueOfThisField) && currentValueOfThisField.Length > maxLengthOfThisColumn)
{
longFields.Add(dbColumn.Key, $"'{dbColumn.Key}' column cannot take the value of '{currentValueOfThisField}' because the max length it can take is {maxLengthOfThisColumn}.");
}
}
return longFields;
}
public static List<PropertyInfo> GetProperties<T>(T entity)
{
//The DeclaredOnly flag makes sure you only get properties of the object, not from the classes it derives from.
var properties = entity.GetType()
.GetProperties(System.Reflection.BindingFlags.Public
| System.Reflection.BindingFlags.Instance
| System.Reflection.BindingFlags.DeclaredOnly)
.ToList();
return properties;
}
Demo:
Let's say we're trying to insert someTableEntity of SomeTable class that is modeled in our app like so:
public class SomeTable
{
[Key]
public long TicketID { get; set; }
public string SourceData { get; set; }
}
And it's inside our SomeDbContext like so:
public class SomeDbContext : DbContext
{
public DbSet<SomeTable> SomeTables { get; set; }
}
This table in Db has SourceData field as varchar(16) like so:
Now we'll try to insert value that is longer than 16 characters into this field and capture this information:
public void SaveSomeTableEntity()
{
var connectionString = "server=SERVER_NAME;database=DB_NAME;User ID=SOME_ID;Password=SOME_PASSWORD;Connection Timeout=200";
using (var context = new SomeDbContext(connectionString))
{
var someTableEntity = new SomeTable()
{
SourceData = "Blah-Blah-Blah-Blah-Blah-Blah"
};
context.SomeTables.Add(someTableEntity);
try
{
context.SaveChanges();
}
catch (Exception ex)
{
if (ex.GetBaseException().Message == "String or binary data would be truncated.\r\nThe statement has been terminated.")
{
var badFieldsReport = "";
List<string> badFields = new List<string>();
// YOU GOT YOUR FIELDS RIGHT HERE:
var longFields = FindLongBinaryOrStringFields(someTableEntity, connectionString);
foreach (var longField in longFields)
{
badFields.Add(longField.Key);
badFieldsReport += longField.Value + "\n";
}
}
else
throw;
}
}
}
The badFieldsReport will have this value:
'SourceData' column cannot take the value of
'Blah-Blah-Blah-Blah-Blah-Blah' because the max length it can take is
16.
Kevin Pope's comment under the accepted answer was what I needed.
The problem, in my case, was that I had triggers defined on my table that would insert update/insert transactions into an audit table, but the audit table had a data type mismatch where a column with VARCHAR(MAX) in the original table was stored as VARCHAR(1) in the audit table, so my triggers were failing when I would insert anything greater than VARCHAR(1) in the original table column and I would get this error message.
I used a different tactic, fields that are allocated 8K in some places. Here only about 50/100 are used.
declare #NVPN_list as table
nvpn varchar(50)
,nvpn_revision varchar(5)
,nvpn_iteration INT
,mpn_lifecycle varchar(30)
,mfr varchar(100)
,mpn varchar(50)
,mpn_revision varchar(5)
,mpn_iteration INT
-- ...
) INSERT INTO #NVPN_LIST
SELECT left(nvpn ,50) as nvpn
,left(nvpn_revision ,10) as nvpn_revision
,nvpn_iteration
,left(mpn_lifecycle ,30)
,left(mfr ,100)
,left(mpn ,50)
,left(mpn_revision ,5)
,mpn_iteration
,left(mfr_order_num ,50)
FROM [DASHBOARD].[dbo].[mpnAttributes] (NOLOCK) mpna
I wanted speed, since I have 1M total records, and load 28K of them.
This error may be due to less field size than your entered data.
For e.g. if you have data type nvarchar(7) and if your value is 'aaaaddddf' then error is shown as:
string or binary data would be truncated
You simply can't beat SQL Server on this.
You can insert into a new table like this:
select foo, bar
into tmp_new_table_to_dispose_later
from my_table
and compare the table definition with the real table you want to insert the data into.
Sometime it's helpful sometimes it's not.
If you try inserting in the final/real table from that temporary table it may just work (due to data conversion working differently than SSMS for example).
Another alternative is to insert the data in chunks, instead of inserting everything immediately you insert with top 1000 and you repeat the process, till you find a chunk with an error. At least you have better visibility on what's not fitting into the table.
I have the following a homework assignment:
A company firewall monitors all internet connections and logs them into a CSV file with the following format:
date_time;src_IP;src_port;dst_IP;dst_port;data_size;
Example:
2017-12-31/22:31:15;192.168.1.23;23899;77.75.77.53;80;289456;
2017-12-31/22:31:15;192.168.1.23;23901;77.75.77.53;80;289456;
2017-12-31/22:31:48;192.168.1.23;23902;77.75.77.53;80;2903;
As you can see, the date_time column is not unique. Only the combination of all the data in one row is unique.
You can parse the data by using SimpleDateFormat("yyyy-MM-dd/HH:mm:ss").
Create a program, which will read the whole CSV into a Set and will be able to quickly find an offending employee by the time, IP address and/or port of the internet access.
I really can't solve it, so any help will be appreciated!
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
// TODO Auto-generated method stub
// my task:
//ask the user for the offending IP address
//then while reading the csv print all the lines which
//contains the offending IP address (it could be either dest. IP address or source IP)
// the user can also give u a date of the attack.
//then u must print only lines with the given date.
String Ipaddr = "192.168.1.23";
try {
Scanner s = new Scanner(new File("data.csv"));
while (s.hasNext()) {
String line = s.nextLine();
String items [] = line.split(";");
System.out.println(Arrays.deepToString(items));
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
You can define and initialize a field like this:
Map<Date, Set<Employee>> employees = new HashMap<>();
And Employee contains:
class Employee {
String sourceIp; // src_ip
String sourcePort; // src_port
String destinationIp; // dst_ip
String destinationPort; // dst_port
int dataSize; // data_size
}
According to your code, the part of while loop can be changed to:
while (s.hasNext()) {
String line = s.nextLine();
String items [] = line.split(";");
Date date = dateFormat.parse(items[0]);
if(!employees.containsKey(date)) {
employees.put(date, new HashSet<>());
}
Employee employee = new Employee();
// Put src_ip, src_port, dst_ip ... etc into the variable 'employee'
employees.get(date).add(employee);
}
Variable dateFormat is equal to SimpleDateFormat.
You can get Employees values set using the field we initialized before.
Set<Employee> employees = employees.get(specificDate);
Start top-down:
A company firewall monitors all internet connections and logs them into a CSV file...
Create a program, which will read the whole CSV into a Set and will be able to quickly find an offending employee by the time, IP address and/or port of the internet access.
This will in something like:
Set<LogLine> internetTraffic = readInternetTraffic("/var/logs/itraf.log", internetTraffic);
... // Data structures
List<Employee> findOffendingEmployeesByTimeIP(...);
List<Employee> findOffendingEmployeesByTimePort(...);
As I doubt that findBy-methods will be optimal using the entire Set only, but will profit by maps or a sorting on time and such, you might want to process the Set
during or after the reading.
Useful: a sub map with keys in a range.
List<Employee> find(LocalDateTime from, LocalDateTime to, ...) {
SortedMap<LocalDateTime, LogLine> map = new TreeMap<>();
...
SortedMap<LocalDateTime, LogLine> submap = map.subMap​(from, to);
The exact data structure(s) to derive from Set<LogLine> for the retrieval method(s) you will construct as needed.
First of all, I'm not sure about if the title or the tags are correct. If not, someone please correct me
My question is if there are any tools or ways to create an autocomplete list with items from an external source, having netbeans parsing it and warn me if there are any errors.
-- The problem: I use JDBC and I want to model somehow all my schemas, tables and columns so that netbeans can parse it and warn me if I have anything wrong. For example with a normal use of JDBC I would had a function:
ResultSet execSelect( String cols, String table ){
return statement.executeQuery("SELECT "+cols+" FROM "+table); }
The problem is that someone should know exactly what are the available params for that to pass the correct strings.
I would like netbeans to show me somehow an autocomplete list with all available options.
PS. I had exactly the same problem when I was building a web application and I wanted somehow to get all paths for my external resources like images, .js files, .css files etc.
-- Thoughts so far:
My thoughts till now were to put a .java file with public static final String vars with some how nested static classes so that I could access from anywhere. For example:
DatabaseModel.MySchema.TableName1.ColumnName2
would be a String varialble with the 'ColumnName2' column and 'TableName1' table. That would help me with autocompletes but the problem is that there is no type checking. In other words someone could use any string, global defined or not as a table and as a column which is not correct either. I'm thinking to use nested enums somehow to cover these cases about type checking but I'm not sure if that would be a good solution in any case.
Any thoughts?
Finally I came up with writting a "script" that connects to mysql gets all meta data (every column of every table of every schema) and creates a java file with predefined classes and Strings that describes the model. For example:
- If you want the name of the column C1 from table T1 from schema S1 you would type DatabaseModel.S1.T1.C1._ which is a public static final String with the column name.
- If you want the table T2 from schema S2 you would type DatabaseModel.S2.T2 which is a class that implements DatabaseTable interface. So the function: execSelect could take a DatabaseTable and a DatabaseColumn as a parameter.
Here is the code (not tested but the idea is clear I think).
public static void generateMysqlModel(String outputFile) throws IOException, SQLException{
//** Gather the database model
// Maps a schema -> table -> column
HashMap<String,HashMap<String,ArrayList<String>>> model =
new HashMap<String,HashMap<String,ArrayList<String>>>();
openDatabase();
Connection sqlConn = DriverManager.getConnection(url, username, password);
DatabaseMetaData md = sqlConn.getMetaData();
ResultSet schemas = md.getSchemas(); // Get schemas
while( schemas.next() ){ // For every schema
String schemaName = schemas.getString(1);
model.put( schemaName, new HashMap<String,ArrayList<String>>() );
ResultSet tables = md.getTables(null, null, "%", null); // Get tables
while (tables.next()) { // For every table
String tableName = tables.getString(3);
model.get(schemaName).put( tableName, new ArrayList<String>() );
// Get columns for table
Statement s = sqlConn.createStatement(); // Get columns
s.execute("show columns in "+tables.getString(3)+";");
ResultSet columns = s.getResultSet();
while( columns.next() ){ // For every column
String columnName = columns.getString(1);
model.get(schemaName).get(tableName).add( columnName );
}
}
}
closeDatabase();
//** Create the java file from the collected model
new File(outputFile).createNewFile();
BufferedWriter bw = new BufferedWriter( new FileWriter(outputFile) ) ;
bw.append( "public class DatabaseModel{\n" );
bw.append( "\tpublic interface DatabaseSchema{};\n" );
bw.append( "\tpublic interface DatabaseTable{};\n" );
bw.append( "\tpublic interface DatabaseColumn{};\n\n" );
for( String schema : model.keySet() ){
HashMap<String,ArrayList<String>> schemaTables = model.get(schema);
bw.append( "\tpublic static final class "+schema+" implements DatabaseSchema{\n" );
//bw.append( "\t\tpublic static final String _ = \""+schema+"\";\n" );
for( String table : schemaTables.keySet() ){
System.out.println(table);
ArrayList<String> tableColumns = schemaTables.get(table);
bw.append( "\t\tpublic static final class "+table+" implements DatabaseTable{\n" );
//bw.append( "\t\t\tpublic static final String _ = \""+table+"\";\n" );
for( String column : tableColumns ){
System.out.println("\t"+column);
bw.append( "\t\t\tpublic static final class "+column+" implements DatabaseColumn{"
+ " public static final String _ = \""+column+"\";\n"
+ "}\n" );
}
bw.append( "\t\t\tpublic static String val(){ return this.toString(); }" );
bw.append( "\t\t}\n" );
}
bw.append( "\t\tpublic static String val(){ return this.toString(); }" );
bw.append( "\t}\n" );
}
bw.append( "}\n" );
bw.close();
}
PS. For the resources case in a web application I guess someone could get all files recursively from the "resources" folder and fill in the model variable. That will create a java file with the file paths. The interfaces in that case could be the file types or any other "file view" you want.
I also thought that it would be useful to create the .java file from an XML file for any case, so anyone would just create some kind of defintion in an xml file for that purpose.
If someone implements anything like that can post it here.
Any comments/improvements will be welcomed.