Mar*_*ius 6 java swing jtable poi-hssf apache-poi
我最近开始使用java,当我需要从jTable开始创建一个excel文件时,我遇到了apache poi库的一些问题.
我已经阅读了许多线程,并提出了一些不起作用的代码(即使这很简单,有许多例子,这让我看起来更加愚蠢)而且我希望有人可以帮助我.
所以这里是问题:
a)为什么写入excel文件的for循环不填充每个单元格？(excel文件中唯一包含数据的行是第六行,这也让我想知道为什么它会为getRowCount/Column方法计算表模型中的空项.所以我知道它打印的是自定义String而不是表本身但保留点b)
b)我应该如何使用jtable模型项来填充excel文件,因为在创建表时我必须选择Object作为行类型？(我也遇到了这类对象的问题,只要它是一个字符串||整数就没有任何问题,但是这个表应该是两者的混合,当你尝试时它似乎不起作用使用setCellValue()方法与String || integer ...或至少我无法使其工作的东西
c)假设我之后想要从我之前创建的文件中填充jtable,在使用bufferedReader类读取文件后,我是否只需要使用解决方案指向b)(另一种方法)？
免责声明:代码的第一部分是由netbeans自动生成的,你可以告诉我,我提出的hssf部分是在最后但是我想你可能想看到整件事,抱歉,如果它看起来有点凌乱.
这是代码:
package poitest;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JTable;
import javax.swing.table.TableModel;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
public class POITestFrame extends javax.swing.JFrame {
/**
* Creates new form POITestFrame
*/
public POITestFrame() {
initComponents();
}
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
private void initComponents() {
excelButton = new javax.swing.JButton();
jScrollPane1 = new javax.swing.JScrollPane();
jTable1 = new javax.swing.JTable();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
excelButton.setText("ESPORTA!");
excelButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
excelButtonActionPerformed(evt);
}
});
jTable1.setModel(new javax.swing.table.DefaultTableModel(
new Object [][] {
{"Boolean", "Integer", "String", "Array"},
{"x*y", "x+y", "x/y", "x-y"},
{"32", "43", "12", "24"},
{"casa", "cantiere", "museo", "acquario"},
{null, null, null, null},
{null, null, null, null}
},
new String [] {
"Title 1", "Title 2", "Title 3", "Title 4"
}
));
jScrollPane1.setViewportView(jTable1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 320, Short.MAX_VALUE)
.addComponent(excelButton, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 91, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(excelButton)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
pack();
}// </editor-fold>//GEN-END:initComponents
private void excelButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_excelButtonActionPerformed
try {
PoiWriter(jTable1);
} catch (FileNotFoundException ex) {
Logger.getLogger(POITestFrame.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(POITestFrame.class.getName()).log(Level.SEVERE, null, ex);
}
}//GEN-LAST:event_excelButtonActionPerformed
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/*
* Set the Nimbus look and feel
*/
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/*
* If Nimbus (introduced in Java SE 6) is not available, stay with the
* default look and feel. For details see
* http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(POITestFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(POITestFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(POITestFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(POITestFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/*
* Create and display the form
*/
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new POITestFrame().setVisible(true);
}
});
}
// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JButton excelButton;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTable jTable1;
// End of variables declaration//GEN-END:variables
private void PoiWriter(JTable jTable1) throws FileNotFoundException, IOException {
TableModel model = jTable1.getModel();
// create a workbook
Workbook wb = new HSSFWorkbook(); // xls file
// create a new sheet
Sheet sheet = wb.createSheet("Foglio di Prova!");
// declare a row object reference
Row r = null;
// declare a cell object reference
Cell c = null;
// create a new file
FileOutputStream fos;
fos = new FileOutputStream("File di Prova.xls");
// create a sheet table rows
int rownum;
for (rownum = (short) 0; rownum < model.getRowCount(); rownum++) {
// create a row
r = sheet.createRow(rownum);
}
for (short cellnum = (short) 0; cellnum < model.getRowCount(); cellnum ++) {
// create a numeric cell
c = r.createCell(cellnum);
// populate table with custom objects
for(int i=0; i < model.getRowCount();i++){
for(int j=0;j < model.getColumnCount();j++){
String aplala = "blabla";
c.setCellValue(aplala);
}
}
}
wb.write(fos);
fos.close();
}
}
PS:如果你想知道为什么我用对象类型构建表:这不是我正在使用的项目,我制作了这个片段来测试hssf,因为得到的excel是非常可编辑但事情似乎不是顺利
PPS:我也尝试过使用tokenizer类,但我不确定你是否可以像poi lib一样编辑生成的excel文件.
PPPS:这是我第一次使用java,所以请不要太粗暴!
我希望这些问题足够清楚,并且事先感谢,我正努力在编程方面做得更好:P
编辑:经过一天的练习,这是我想出来的,似乎与apache poi库一起工作,感谢帮助人们提供了很好的指示!
int rowNum;
int colNum;
int tempRows;
int rowCount = model.getRowCount();
int columnCount = model.getColumnCount();
// create the headers
for (colNum = 0; colNum < columnCount; colNum++) {
if (colNum == 0) {
r = sheet.createRow(0);
}
c = r.createCell(colNum);
c.setCellValue(model.getColumnName(colNum));
}
for (rowNum = 0; rowNum < rowCount; rowNum++) {
// create rows + 1 (to account for the headers)
tempRows = rowNum + 1;
r = sheet.createRow(tempRows);
for (short cellnum = 0; cellnum < columnCount; cellnum ++) {
// create cells
c = r.createCell(cellnum);
// add values from table
c.setCellValue(model.getValueAt(rowNum, cellnum).toString());
}
}
如果您认为代码可以改进,请随时发表评论,欢迎提出建议,特别是像我这样的新人;)
再次,感谢您的提示,他们真的做到了^^
请阅读有关JTable,创建表模型和实现数据类型的教程,JTable了解这些Column Classes,并将proper value输出返回到POI; 对于MS Excel中的大多数类型:
你也必须在当前行的单元格内循环
必须为各种数据类型格式化输出(Date,Double,String)
然后你可以专注于创造formula(s)和coloring cell(s)
循环的代码TableModel也可以使用标准生成MS Excel文件windows delimiters:
public class ExcelCustomerReport {
public ExcelCustomerReport() {
}
public void exportTable(JTable table, File file) throws IOException {
TableModel model = table.getModel();
FileWriter out = new FileWriter(file);
String groupExport = "";
for (int i = 0; i < (model.getColumnCount()); i++) {//* disable export from TableHeaders
groupExport = String.valueOf(model.getColumnName(i));
out.write(String.valueOf(groupExport) + "\t");
}
out.write("\n");
for (int i = 0; i < model.getRowCount(); i++) {
for (int j = 0; j < (model.getColumnCount()); j++) {
if (model.getValueAt(i, j) == null) {
out.write("null" + "\t");
} else {
groupExport = String.valueOf(model.getValueAt(i, j));
out.write(String.valueOf(groupExport) + "\t");
}
}
out.write("\n");
}
out.close();
}
}