can anyone help me to reduce cylomatic complexity for below method upto 10..also considering no nesting of if else is allow as it will also cause sonar issue.
It will be great help for me
private void processIntransitFile(String fileName) {
if (StringUtils.isNotBlank(fileName))
return;
// read Intransit folder and do the processing on these files
try (BufferedReader bufferedReader = new BufferedReader(new FileReader(intransitDir + fileName))) {
TokenRangeDTO tokenRangeDTO = new TokenRangeDTO();
int count = 0;
String header = "";
String next;
String line = bufferedReader.readLine();
LinkedHashSet<String> tokenRanges = new LinkedHashSet<>();
int trCount = 0;
boolean first = true;
boolean last = line == null;
while (!last) {
last = (next = bufferedReader.readLine()) == null;
if (!first && !last) {
tokenRanges.add(line);
}
// read first line of the file
else if (first && line.startsWith(H)) {
header = line;
first = false;
} else if (first && !line.startsWith(H)) {
tokenRangeDTO.setValidationMessage(HEADER_MISSING);
first = false;
}
// read last line of the file
else if (last && line.startsWith(T)) {
trCount = getTrailerCount(tokenRangeDTO, line, trCount);
} else if (last && !line.startsWith(T)) {
tokenRangeDTO.setValidationMessage(TRAILOR_MISSING);
}
line = next;
count++;
}
processInputFile(fileName, tokenRangeDTO, count, header, tokenRanges, trCount);
} catch (IOException e) {
LOGGER.error(IO_EXCEPTION, e);
} catch (Exception e) {
LOGGER.error("Some exception has occured", e);
} finally {
try {
FileUtils.deleteQuietly(new File(intransitDir + fileName));
} catch (Exception ex) {
LOGGER.error(STREAM_FAILURE, ex);
}
}
}
can anyone help me to reduce cylomatic complexity for below method upto 10..also considering no nesting of if else is allow as it will also cause sonar issue.
It will be great help for me
You could extract part of your code to methods and/or refactor some variables which could be used in other way. Also, when you have comments explaining your code it is a strong indicator that your logic can be improved there:
private void processIntransitFile(String fileName) {
if (StringUtils.isNotBlank(fileName)) return;
processFromIntransitDirectory(fileName);
}
private void processFromIntransitDirectory(String fileName) {
try (BufferedReader bufferedReader = new BufferedReader(getFileFromIntransitFolder(fileName))) {
TokenRangeDTO tokenRangeDTO = new TokenRangeDTO();
int count = 0;
String header = "";
String next;
String line = bufferedReader.readLine();
LinkedHashSet<String> tokenRanges = new LinkedHashSet<>();
int trCount = 0;
while (!isLastLine(line)) {
next = bufferedReader.readLine();
if (!isFirstLine(count) && !isLastLine(next)) {
tokenRanges.add(line);
}
header = readFirstLine(line, count, tokenRangeDTO);
trCount = readLastLine(line, next, trCount, tokenRangeDTO);
line = next;
count++;
}
processInputFile(fileName, tokenRangeDTO, count, header, tokenRanges, trCount);
} catch (IOException e) {
LOGGER.error(IO_EXCEPTION, e);
} catch (Exception e) {
LOGGER.error("Some exception has occured", e);
} finally {
try {
FileUtils.deleteQuietly(new File(intransitDir + fileName));
} catch (Exception ex) {
LOGGER.error(STREAM_FAILURE, ex);
}
}
}
private boolean isLastLine(String line) {
return line != null;
}
private String readFirstLine(String line, int count, TokenRangeDTO tokenRangeDTO) {
if (isFirstLine(count) && isHeader(line)) {
return line;
} else if (isFirstLine(count) && !isHeader(line)) {
tokenRangeDTO.setValidationMessage(HEADER_MISSING);
}
return StringUtils.EMPTY;
}
private int readLastLine(String line, String next, int trCount, TokenRangeDTO tokenRangeDTO){
if (isLastLine(next) && isTrailor(line)) {
return getTrailerCount(tokenRangeDTO, line, trCount);
} else if (last && !isTrailor(line)) {
tokenRangeDTO.setValidationMessage(TRAILOR_MISSING);
}
return 0;
}
private boolean isTrailor(String line) {
return line.startsWith(T);
}
private boolean isHeader(String line) {
return line.startsWith(H);
}
private boolean isFirstLine(int count) {
return count == 0;
}
private FileReader getFileFromIntransitFolder(String fileName) {
return new FileReader(intransitDir + fileName);
}
Doing this your code will be more readable, you will avoid useless variables using logic and your cyclomatic complexity will decrease.
For more tips, I recommend access refactoring.guru.
I have a huge CSV file ~800 K records and using that data I have to form a POST request and make a rest call.
Initially I tried WITHOUT using threads but it is taking very long time to process it.
So I thought of using threads to speed up the process and followed below approach.
divided file into relatively smaller files (Tried with 3 files with approx ~5K data each file). (I Did this Manually Before passing to application)
Created 3 threads (traditional way by extending Thread class)
Reads each file with each thread and form HashMap with details required to form request and added it to ArrayList of POST Request
Send Post request to in loop
List item
Get the Response and add it to Response List
Both above approach takes too long to even complete half (>3 hrs). Might be one of them would not be good approach.
Could anyone please provide suggestion which helps me speeding up the process ? It is NOT mandatory to use threading.
Just to add that my code is at the consumer end and does not have much control on producer end.
MultiThreadedFileRead (Main class that Extends Thread)
class MultiThreadedFileRead extends Thread
{
public static final String EMPTY = "";
public static Logger logger = Logger.getLogger(MultiThreadedFileRead.class);
BufferedReader bReader = null;
String filename = null;
int Request_Num = 0;
HashMap<Integer, String> filteredSrcDataMap = null;
List<BrandRQ> brandRQList = null;
List<BrandRS> brandRSList = null;
ReadDLShipFile readDLShipFile = new ReadDLShipFile();
GenerateAndProcessPostBrandAPI generateAndProcessPostBrandAPI = new GenerateAndProcessPostBrandAPI();
MultiThreadedFileRead()
{
}
MultiThreadedFileRead(String fname) throws Exception
{
filename = fname;
Request_Num = 0;
List<BrandRQ> brandRQList = new ArrayList<BrandRQ>();
List<BrandRS> brandRSList = new ArrayList<BrandRS>();
this.start();
}
public void run()
{
logger.debug("File *** : " + this.filename);
//Generate Source Data Map
HashMap<Integer, String> filteredSrcDataMap = (HashMap<Integer, String>) readDLShipFile.readSourceFileData(this.filename);
generateAndProcessPostBrandAPI.generateAndProcessPostRequest(filteredSrcDataMap, this);
}
public static void main(String args[]) throws Exception
{
String environment = ""; // TO BE UNCOMMENTED
String outPutfileName = ""; // TO BE UNCOMMENTED
BrandRetrivalProperties brProps = BrandRetrivalProperties.getInstance();
if(args != null && args.length == 2 && DLPremiumUtil.isNotEmpty(args[0]) && DLPremiumUtil.isNotEmpty(args[1])) // TO BE UNCOMMENTED
{
environment = args[0].trim();
outPutfileName = args[1].trim();
ApplicationInitializer applicationInitializer = new ApplicationInitializer(environment);
applicationInitializer.initializeParams();
logger.debug("Environment : " + environment);
logger.debug("Filename : " + outPutfileName);
// TO BE UNCOMMENTED - START
}else{
System.out.println("Invalid parameters passed. Expected paramenters: Environment");
System.out.println("Sample Request: java -jar BrandRetrival.jar [prd|int] brand.dat");
System.exit(1);
}
MultiThreadedFileRead multiThreadedFileRead = new MultiThreadedFileRead();
List<String> listOfFileNames = multiThreadedFileRead.getFileNames(brProps);
logger.debug("List : " + listOfFileNames);
int totalFileSize = listOfFileNames.size();
logger.debug("totalFileSize : " + totalFileSize);
MultiThreadedFileRead fr[]=new MultiThreadedFileRead[totalFileSize];
logger.debug("Size of Array : " + fr.length);
for(int i = 0; i < totalFileSize; i++)
{
logger.debug("\nFile Getting Added to Array : " + brProps.getCountFilePath()+listOfFileNames.get(i));
fr[i]=new MultiThreadedFileRead(brProps.getCountFilePath()+listOfFileNames.get(i));
}
}
public List<String> getFileNames(BrandRetrivalProperties brProps)
{
MultiThreadedFileRead multiThreadedFileRead1 = new MultiThreadedFileRead();
BufferedReader br = null;
String line = "";
String filename = multiThreadedFileRead1.getCounterFileName(brProps.getCountFilePath(), brProps.getCountFilePathStartsWith());
List<String> fileNameList = null;
logger.debug("filename : " + filename);
if(filename != null)
{
fileNameList = new ArrayList<String>();
try{
br = new BufferedReader(new FileReader(brProps.getCountFilePath()+filename));
while ((line = br.readLine()) != null)
{
fileNameList.add(line);
}
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e2) {
// TODO Auto-generated catch block ;
e2.printStackTrace();
} catch (Exception e3) {
// TODO Auto-generated catch block
e3.printStackTrace();
} finally
{
if (br != null)
{
try
{
br.close();
} catch (IOException e4)
{
e4.printStackTrace();
} catch (Exception e5)
{
e5.printStackTrace();
}
}
}
}
return fileNameList;
}
// Get the Name of the file which has name of individual CSV files to read to form the request
public String getCounterFileName(String sourceFilePath, String sourceFileNameStartsWith)
{
String fileName = null;
if(sourceFilePath != null && !sourceFilePath.equals(EMPTY) &&
sourceFileNameStartsWith != null && !sourceFileNameStartsWith.equals(EMPTY))
{
File filePath = new File(sourceFilePath);
File[] listOfFiles = filePath.listFiles();
for (int i = 0; i < listOfFiles.length; i++) {
if (listOfFiles[i].isFile() && listOfFiles[i].getName().startsWith(sourceFileNameStartsWith)) {
fileName = listOfFiles[i].getName();
} else if (listOfFiles[i].isDirectory()) {
fileName = null;
}
}
}
return fileName;
}
}
GenerateAndProcessPostBrandAPI
public class GenerateAndProcessPostBrandAPI {
public static Logger logger = Logger.getLogger(GenerateAndProcessPostBrandAPI.class);
List<BrandRQ> brandRQList = new ArrayList<BrandRQ>();
List<BrandRS> brandRSList = new ArrayList<BrandRS>();
DLPremiumClientPost dlPremiumclientPost = new DLPremiumClientPost();
JSONRequestGenerator jsonRequestGenerator = new JSONRequestGenerator();
public List<BrandRQ> getBrandRequstList(Map<Integer, String> filteredSrcDataMap)
{
if(filteredSrcDataMap != null)
{
brandRQList = jsonRequestGenerator.getBrandRQList(filteredSrcDataMap, brandRQList);
}
return brandRQList;
}
public void generateAndProcessPostRequest(Map<Integer, String> filteredSrcDataMap, MultiThreadedFileRead multiThreadedFileRead)
{
if(filteredSrcDataMap != null)
{
brandRQList = jsonRequestGenerator.getBrandRQList(filteredSrcDataMap, brandRQList);
if(brandRQList != null && brandRQList.size() > 0)
{
BrandRetrivalProperties brProps = BrandRetrivalProperties.getInstance();
String postBrandsEndpoint = brProps.getPostBrandsEndPoint();
for (BrandRQ brandRQ : brandRQList)
{
multiThreadedFileRead.Request_Num = multiThreadedFileRead.Request_Num + 1;
logger.debug("Brand Request - " + multiThreadedFileRead.Request_Num + " : " + ObjectToJSONCovertor.converToJSON(brandRQ));
BrandRS brandResponse = dlPremiumclientPost.loadBrandApiResponseJSON(brandRQ, postBrandsEndpoint, DLPremiumUtil.getTransactionID(), BrandConstants.AUTH_TOKEN);
logger.debug("Response - " + multiThreadedFileRead.Request_Num + " : " + ObjectToJSONCovertor.converToJSON(brandResponse));
brandRSList.add(brandResponse);
}
}
}
}
}
I'm trying to fix a bug in the code I wrote which convert a srt file to dxfp.xml. it works fine but when there is a special character such as an ampersand it throws an java.lang.NumberFormatException error. I tried to use the StringEscapeUtils function from apache commons to solve it. Can someone explain to me what it is I am missing here? thanks in advance!
public class SRT_TO_DFXP_Converter {
File input_file;
File output_file;
ArrayList<CaptionLine> node_list;
public SRT_TO_DFXP_Converter(File input_file, File output_file) {
this.input_file = input_file;
this.output_file = output_file;
this.node_list = new ArrayList<CaptionLine>();
}
class CaptionLine {
int line_num;
String begin_time;
String end_time;
ArrayList<String> content;
public CaptionLine(int line_num, String begin_time, String end_time,
ArrayList<String> content) {
this.line_num = line_num;
this.end_time = end_time;
this.begin_time = begin_time;
this.content = content;
}
public String toString() {
return (line_num + ": " + begin_time + " --> " + end_time + "\n" + content);
}
}
private void readSRT() {
BufferedReader bis = null;
FileReader fis = null;
String line = null;
CaptionLine node;
Integer line_num;
String[] time_split;
String begin_time;
String end_time;
try {
fis = new FileReader(input_file);
bis = new BufferedReader(fis);
do {
line = bis.readLine();
line_num = Integer.valueOf(line);
line = bis.readLine();
time_split = line.split(" --> ");
begin_time = time_split[0];
begin_time = begin_time.replace(',', '.');
end_time = time_split[1];
end_time.replace(',', '.');
ArrayList<String> content = new ArrayList<String>();
while (((line = bis.readLine()) != null)
&& (!(line.trim().equals("")))) {
content.add(StringEscapeUtils.escapeJava(line));
//if (StringUtils.isEmpty(line)) break;
}
node = new CaptionLine(line_num, begin_time, end_time, content);
node_list.add(node);
} while (line != null);
} catch (Exception e) {
System.out.println(e);
}
finally {
if (bis != null) {
try {
bis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
private String convertToXML() {
StringBuffer dfxp = new StringBuffer();
dfxp.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<tt xml:lang=\"en\" xmlns=\"http://www.w3.org/2006/04/ttaf1\" xmlns:tts=\"http://www.w3.org/2006/04/ttaf1#styling\">\n\t<head>\n\t\t<styling>\n\t\t\t<style id=\"1\" tts:backgroundColor=\"black\" tts:fontFamily=\"Arial\" tts:fontSize=\"14\" tts:color=\"white\" tts:textAlign=\"center\" tts:fontStyle=\"Plain\" />\n\t\t</styling>\n\t</head>\n\t<body>\n\t<div xml:lang=\"en\" style=\"default\">\n\t\t<div xml:lang=\"en\">\n");
for (int i = 0; i < node_list.size(); i++) {
dfxp.append("\t\t\t<p begin=\"" + node_list.get(i).begin_time + "\" ")
.append("end=\"" + node_list.get(i).end_time
+ "\" style=\"1\">");
for (int k = 0; k < node_list.get(i).content.size(); k++) {
dfxp.append("" + node_list.get(i).content.get(k));
}
dfxp.append("</p>\n");
}
dfxp.append("\t\t</div>\n\t</body>\n</tt>\n");
return dfxp.toString();
}
private void writeXML(String dfxp) {
BufferedWriter out = null;
try {
out = new BufferedWriter(new FileWriter(output_file));
out.write(dfxp);
out.close();
} catch (IOException e) {
System.out.println("Error Writing To File:"+ input_file +'\n');
e.printStackTrace();
} finally {
if (out != null) {
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
public static void main(String[] args) {
if ((args.length < 2) || (args[1].equals("-h"))) {
System.out.println("\n<--- SRT to DFXP Converter Usage --->");
System.out
.println("Conversion: java -jar SRT_TO_DFXP.jar <input_file> <output_file> [-d]");
System.out
.println("Conversion REQUIRES a input file and output file");
System.out.println("[-d] Will Display XML Generated In Console");
System.out.println("Help: java -jar SRT_TO_DFXP.jar -h");
} else if (!(new File(args[0]).exists())) {
System.out.println("Error: Input SubScript File Does Not Exist\n");
} else {
SRT_TO_DFXP_Converter converter = new SRT_TO_DFXP_Converter(
new File(args[0]), new File(args[1]));
converter.readSRT();
String dfxp = converter.convertToXML();
if ((args.length == 3) && (args[2].equals("-d")))
System.out.println("\n" + dfxp + "\n");
converter.writeXML(dfxp);
System.out.println("Conversion Complete");
}
}
here's part of the srt file that it is throwing an error when exported and run as a jar file.
1
00:20:43,133 --> 00:20:50,599
literature and paper by Liversmith & Newman, and I think the point is well made that a host of factors
I am developing a voice-based app in android and facing some problems please see below code,
Java File 1
file = .wav file
public static AudioInputStream getAudioInputStream(File file) throws UnsupportedAudioFileException, IOException {
return getAudioInputStreamImpl(file);
}
private static AudioInputStream getAudioInputStreamImpl(Object source) throws UnsupportedAudioFileException, IOException {
GetAudioInputStreamAudioFileReaderAction action = new GetAudioInputStreamAudioFileReaderAction(source);
doAudioFileReaderIteration(action);
AudioInputStream audioInputStream = action.getAudioInputStream();
if (audioInputStream != null) {
return audioInputStream;
}
throw new UnsupportedAudioFileException("format not supported");
}
private static void doAudioFileReaderIteration(AudioFileReaderAction action) throws IOException {
Iterator audioFileReaders = TAudioConfig.getAudioFileReaders();
boolean bCompleted = false;
while (audioFileReaders.hasNext() && !bCompleted) {
AudioFileReader audioFileReader = (AudioFileReader) audioFileReaders.next();
bCompleted = action.handleAudioFileReader(audioFileReader);
}
}
Java file 2 (TAudioConfig)
public static synchronized Iterator<AudioFileReader> getAudioFileReaders() {
Iterator<AudioFileReader> it;
synchronized (TAudioConfig.class) {
it = getAudioFileReadersImpl().iterator();
}
return it;
}
private static synchronized Set<AudioFileReader> getAudioFileReadersImpl() {
Set<AudioFileReader> set;
synchronized (TAudioConfig.class) {
if (sm_audioFileReaders == null) {
sm_audioFileReaders = new ArraySet();
registerAudioFileReaders();
}
set = sm_audioFileReaders;
}
return set;
}
private static void registerAudioFileReaders() {
TInit.registerClasses(AudioFileReader.class, new C00001());
}
Java File 3 (TInit)
public static void registerClasses(Class providerClass, ProviderRegistrationAction action) {
Iterator providers = Service.providers(providerClass);
if (providers != null) {
while (providers.hasNext()) {
try {
action.register(providers.next());
} catch (Throwable e) {
}
}
}
}
Java File 4 (Service)
public static Iterator<?> providers(Class<?> cls) {
String strFullName = "com/example/voiceautomator/AudioFileReader.class";
Iterator<?> iterator = createInstancesList(strFullName).iterator();
return iterator;
}
private static List<Object> createInstancesList(String strFullName) {
List<Object> providers = new ArrayList<Object>();
Iterator<?> classNames = createClassNames(strFullName);
if (classNames != null) {
while (classNames.hasNext()) {
String strClassName = (String) classNames.next();
try {
Class<?> cls = Class.forName(strClassName, REVERSE_ORDER, ClassLoader.getSystemClassLoader());
providers.add(0, cls.newInstance());
} catch (Throwable e) {
}
}
}
return providers;
}
private static Iterator<String> createClassNames(String strFullName) {
Set<String> providers = new ArraySet<String>();
Enumeration<?> configs = null;
try {
configs = Service.class.getClassLoader().getSystemResources(strFullName);
} catch (Throwable e) {
}
if (configs != null) {
while (configs.hasMoreElements()) {
URL configFileUrl = (URL) configs.nextElement();
InputStream input = null;
try {
input = configFileUrl.openStream();
} catch (Throwable e2) {
}
if (input != null) {
BufferedReader reader = new BufferedReader(new InputStreamReader(input));
try {
for (String strLine = reader.readLine(); strLine != null; strLine = reader.readLine()) {
strLine = strLine.trim();
int nPos = strLine.indexOf(35);
if (nPos >= 0) {
strLine = strLine.substring(0, nPos);
}
if (strLine.length() > 0) {
providers.add(strLine);
}
}
} catch (Throwable e22) {
}
}
}
}
Iterator<String> iterator = providers.iterator();
return iterator;
}
getClassLoader().getSystemResources in the Java File 4 (Service) gives me TwoEnumerationsInOne and configs.hasMoreElements() gives false so not able to go into while loop.
AudioFileReader.java is included in the package
Please guide me to resolve this issue?
Please don't forget I am working on this code in an android project
Please see the value of configs here
http://capsicumtech.in/Screenshot_1.png
Thanks in advance.
I want to write a Object into CSV file.
For XML we have XStream like this
So if i want to convert object to CSV do we have any such library ?
EDIT:
I want to pass my list of Bean to a method which should write all the fields of bean to CSV.
First, serialization is writing the object to a file 'as it is'. AFAIK, you cannot choose file formats and all. The serialized object (in a file) has its own 'file format'
If you want to write the contents of an object (or a list of objects) to a CSV file, you can do it yourself, it should not be complex.
Looks like Java CSV Library can do this, but I have not tried this myself.
EDIT: See following sample. This is by no way foolproof, but you can build on this.
//European countries use ";" as
//CSV separator because "," is their digit separator
private static final String CSV_SEPARATOR = ",";
private static void writeToCSV(ArrayList<Product> productList)
{
try
{
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("products.csv"), "UTF-8"));
for (Product product : productList)
{
StringBuffer oneLine = new StringBuffer();
oneLine.append(product.getId() <=0 ? "" : product.getId());
oneLine.append(CSV_SEPARATOR);
oneLine.append(product.getName().trim().length() == 0? "" : product.getName());
oneLine.append(CSV_SEPARATOR);
oneLine.append(product.getCostPrice() < 0 ? "" : product.getCostPrice());
oneLine.append(CSV_SEPARATOR);
oneLine.append(product.isVatApplicable() ? "Yes" : "No");
bw.write(oneLine.toString());
bw.newLine();
}
bw.flush();
bw.close();
}
catch (UnsupportedEncodingException e) {}
catch (FileNotFoundException e){}
catch (IOException e){}
}
This is product (getters and setters hidden for readability):
class Product
{
private long id;
private String name;
private double costPrice;
private boolean vatApplicable;
}
And this is how I tested:
public static void main(String[] args)
{
ArrayList<Product> productList = new ArrayList<Product>();
productList.add(new Product(1, "Pen", 2.00, false));
productList.add(new Product(2, "TV", 300, true));
productList.add(new Product(3, "iPhone", 500, true));
writeToCSV(productList);
}
Hope this helps.
Cheers.
For easy CSV access, there is a library called OpenCSV. It really ease access to CSV file content.
EDIT
According to your update, I consider all previous replies as incorrect (due to their low-levelness). You can then go a completely diffferent way, the hibernate way, in fact !
By using the CsvJdbc driver, you can load your CSV files as JDBC data source, and then directly map your beans to this datasource.
I would have talked to you about CSVObjects, but as the site seems broken, I fear the lib is unavailable nowadays.
Two options I just ran into:
http://sojo.sourceforge.net/
http://supercsv.sourceforge.net/
It would be interesting to have a csv serializer as it would take up the minimal space compared to other serializing method.
The closest support for java object to csv is stringutils provided by spring utils project
arrayToCommaDelimitedString(Object[] arr) but it is far from being a serializer.
Here is a simple utility which uses reflection to serialize value objects
public class CSVWriter
{
private static String produceCsvData(Object[] data) throws IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
if(data.length==0)
{
return "";
}
Class classType = data[0].getClass();
StringBuilder builder = new StringBuilder();
Method[] methods = classType.getDeclaredMethods();
for(Method m : methods)
{
if(m.getParameterTypes().length==0)
{
if(m.getName().startsWith("get"))
{
builder.append(m.getName().substring(3)).append(',');
}
else if(m.getName().startsWith("is"))
{
builder.append(m.getName().substring(2)).append(',');
}
}
}
builder.deleteCharAt(builder.length()-1);
builder.append('\n');
for(Object d : data)
{
for(Method m : methods)
{
if(m.getParameterTypes().length==0)
{
if(m.getName().startsWith("get") || m.getName().startsWith("is"))
{
System.out.println(m.invoke(d).toString());
builder.append(m.invoke(d).toString()).append(',');
}
}
}
builder.append('\n');
}
builder.deleteCharAt(builder.length()-1);
return builder.toString();
}
public static boolean generateCSV(File csvFileName,Object[] data)
{
FileWriter fw = null;
try
{
fw = new FileWriter(csvFileName);
if(!csvFileName.exists())
csvFileName.createNewFile();
fw.write(produceCsvData(data));
fw.flush();
}
catch(Exception e)
{
System.out.println("Error while generating csv from data. Error message : " + e.getMessage());
e.printStackTrace();
return false;
}
finally
{
if(fw!=null)
{
try
{
fw.close();
}
catch(Exception e)
{
}
fw=null;
}
}
return true;
}
}
Here is an example value object
public class Product {
private String name;
private double price;
private int identifier;
private boolean isVatApplicable;
public Product(String name, double price, int identifier,
boolean isVatApplicable) {
super();
this.name = name;
this.price = price;
this.identifier = identifier;
this.isVatApplicable = isVatApplicable;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPrice() {
return price;
}
public void setPrice(long price) {
this.price = price;
}
public int getIdentifier() {
return identifier;
}
public void setIdentifier(int identifier) {
this.identifier = identifier;
}
public boolean isVatApplicable() {
return isVatApplicable;
}
public void setVatApplicable(boolean isVatApplicable) {
this.isVatApplicable = isVatApplicable;
}
}
and the code to run the util
public class TestCSV
{
public static void main(String... a)
{
Product[] list = new Product[5];
list[0] = new Product("dvd", 24.99, 967, true);
list[1] = new Product("pen", 4.99, 162, false);
list[2] = new Product("ipad", 624.99, 234, true);
list[3] = new Product("crayons", 4.99,127, false);
list[4] = new Product("laptop", 1444.99, 997, true);
CSVWriter.generateCSV(new File("C:\\products.csv"),list);
}
}
Output:
Name VatApplicable Price Identifier
dvd true 24.99 967
pen false 4.99 162
ipad true 624.99 234
crayons false 4.99 127
laptop true 1444.99 997
I wrote a simple class that uses OpenCSV and has two static public methods.
static public File toCSVFile(Object object, String path, String name) {
File pathFile = new File(path);
pathFile.mkdirs();
File returnFile = new File(path + name);
try {
CSVWriter writer = new CSVWriter(new FileWriter(returnFile));
writer.writeNext(new String[]{"Member Name in Code", "Stored Value", "Type of Value"});
for (Field field : object.getClass().getDeclaredFields()) {
writer.writeNext(new String[]{field.getName(), field.get(object).toString(), field.getType().getName()});
}
writer.flush();
writer.close();
return returnFile;
} catch (IOException e) {
Log.e("EasyStorage", "Easy Storage toCSVFile failed.", e);
return null;
} catch (IllegalAccessException e) {
Log.e("EasyStorage", "Easy Storage toCSVFile failed.", e);
return null;
}
}
static public void fromCSVFile(Object object, File file) {
try {
CSVReader reader = new CSVReader(new FileReader(file));
String[] nextLine = reader.readNext(); // Ignore the first line.
while ((nextLine = reader.readNext()) != null) {
if (nextLine.length >= 2) {
try {
Field field = object.getClass().getDeclaredField(nextLine[0]);
Class<?> rClass = field.getType();
if (rClass == String.class) {
field.set(object, nextLine[1]);
} else if (rClass == int.class) {
field.set(object, Integer.parseInt(nextLine[1]));
} else if (rClass == boolean.class) {
field.set(object, Boolean.parseBoolean(nextLine[1]));
} else if (rClass == float.class) {
field.set(object, Float.parseFloat(nextLine[1]));
} else if (rClass == long.class) {
field.set(object, Long.parseLong(nextLine[1]));
} else if (rClass == short.class) {
field.set(object, Short.parseShort(nextLine[1]));
} else if (rClass == double.class) {
field.set(object, Double.parseDouble(nextLine[1]));
} else if (rClass == byte.class) {
field.set(object, Byte.parseByte(nextLine[1]));
} else if (rClass == char.class) {
field.set(object, nextLine[1].charAt(0));
} else {
Log.e("EasyStorage", "Easy Storage doesn't yet support extracting " + rClass.getSimpleName() + " from CSV files.");
}
} catch (NoSuchFieldException e) {
Log.e("EasyStorage", "Easy Storage fromCSVFile failed.", e);
} catch (IllegalAccessException e) {
Log.e("EasyStorage", "Easy Storage fromCSVFile failed.", e);
}
} // Close if (nextLine.length >= 2)
} // Close while ((nextLine = reader.readNext()) != null)
} catch (FileNotFoundException e) {
Log.e("EasyStorage", "Easy Storage fromCSVFile failed.", e);
} catch (IOException e) {
Log.e("EasyStorage", "Easy Storage fromCSVFile failed.", e);
} catch (IllegalArgumentException e) {
Log.e("EasyStorage", "Easy Storage fromCSVFile failed.", e);
}
}
I think with some simple recursion these methods could be modified to handle any Java object, but for me this was adequate.
Though its very late reply, I have faced this problem of exporting java entites to CSV, EXCEL etc in various projects, Where we need to provide export feature on UI.
I have created my own light weight framework. It works with any Java Beans, You just need to add annotations on fields you want to export to CSV, Excel etc.
Link: https://github.com/abhisoni96/dev-tools
Worth mentioning that the handlebar library https://github.com/jknack/handlebars.java can trivialize many transformation tasks include toCSV.
You can use gererics to work for any class
public class FileUtils<T> {
public String createReport(String filePath, List<T> t) {
if (t.isEmpty()) {
return null;
}
List<String> reportData = new ArrayList<String>();
addDataToReport(t.get(0), reportData, 0);
for (T k : t) {
addDataToReport(k, reportData, 1);
}
return !dumpReport(filePath, reportData) ? null : filePath;
}
public static Boolean dumpReport(String filePath, List<String> lines) {
Boolean isFileCreated = false;
String[] dirs = filePath.split(File.separator);
String baseDir = "";
for (int i = 0; i < dirs.length - 1; i++) {
baseDir += " " + dirs[i];
}
baseDir = baseDir.replace(" ", "/");
File base = new File(baseDir);
base.mkdirs();
File file = new File(filePath);
try {
if (!file.exists())
file.createNewFile();
} catch (Exception e) {
e.printStackTrace();
return isFileCreated;
}
try (BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(new FileOutputStream(file), System.getProperty("file.encoding")))) {
for (String line : lines) {
writer.write(line + System.lineSeparator());
}
} catch (IOException e) {
e.printStackTrace();
return false;
}
return true;
}
void addDataToReport(T t, List<String> reportData, int index) {
String[] jsonObjectAsArray = new Gson().toJson(t).replace("{", "").replace("}", "").split(",\"");
StringBuilder row = new StringBuilder();
for (int i = 0; i < jsonObjectAsArray.length; i++) {
String str = jsonObjectAsArray[i];
str = str.replaceFirst(":", "_").split("_")[index];
if (i == 0) {
if (str != null) {
row.append(str.replace("\"", ""));
} else {
row.append("N/A");
}
} else {
if (str != null) {
row.append(", " + str.replace("\"", ""));
} else {
row.append(", N/A");
}
}
}
reportData.add(row.toString());
}