java封装二维表格代码 java封装二维表格代码是什么

怎样利用Java二维数组制作一个25名同学4个学科的成绩表?

double[][] score = new double[4][25];

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for(int i=0;i4;i++) {

for(int j=0;j25;j++) {

score [i][j] = 100;

System.out.print("第"+j+"个学生的第"+i+"个学科的成绩是"+score [i][j]);

}

}

大概就是这个意思,你可以再加个存学生名字的String数组,和存学科名字的String数组;

例如String[] studentName = new String[25];

studentName[0] = "XiaoMing";

......

String[] subjectName = new String[4];

subjectName[0] = "English";

......

System.out.print("第"+j+"个学生的第"+i+"个学科的成绩是"+score [i][j]);就可以改成

System.out.print(studentName[j]+“的"+subjectName[i]+"成绩是"+score [i][j]);

java 将txt内容读取到二维表

import java.awt.BorderLayout;

import java.awt.Container;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.*;

import java.util.Vector;

import javax.swing.*;

import javax.swing.table.DefaultTableModel;

public class MyFrame extends JFrame implements ActionListener{

JTable table =null;

JLabel lblName =null,lblPwd=null;

JTextField txtName =null,txtPwd =null;

private JButton btnAdd=null,btnUpdate =null,btnDel=null,btnSave=null;

DefaultTableModel model =null;

String path = new String("E:\\my\\Test1\\src\\user.ini");

Container c =null;

public MyFrame(){

lblName = new JLabel("用户名");

lblPwd = new JLabel("密码");

txtName = new JTextField(20);

txtPwd = new JTextField(20);

Vector columns = new Vector();

columns.add("用户名");

columns.add("密码");

Vector vec = readFile();

model = new DefaultTableModel(vec,columns);

table = new JTable(model);

JScrollPane scrollpane = new JScrollPane(table);

table.setRowSelectionAllowed(true);

btnAdd = new JButton("增加");

btnUpdate = new JButton("修改");

btnDel = new JButton("删除");

JPanel p2 = new JPanel();

c = this.getContentPane();

btnAdd.addActionListener(this);

//btnSave.addActionListener(this);

btnUpdate.addActionListener(this);

btnDel.addActionListener(this);

p2.add(lblName);

p2.add(txtName);

p2.add(lblPwd);

p2.add(txtPwd);

p2.add(btnAdd);

p2.add(btnUpdate);

p2.add(btnDel);

c.add(p2,BorderLayout.SOUTH);

c.add(scrollpane);

this.setSize(800,600);

}

@Override

public void actionPerformed(ActionEvent e) {

String [] rows = new String[2];

String id=null;

if(e.getSource() == btnAdd){

String name=txtName.getText().trim();

String pwd = txtPwd.getText().trim();

writeFile(name, pwd);

rows[0] =name;

rows[1] = pwd;

model.addRow(rows);

}else if(e.getSource()== btnSave){

}else if(e.getSource()==btnUpdate){

}

}

public void writeFile(String name,String pwd){

FileWriter writer =null;

BufferedWriter bw =null;

try {

writer= new FileWriter(path,true);

bw = new BufferedWriter(writer);

String context = ":"+"userName="+name+";pwd="+pwd+"\r\n";

bw.write(context);

bw.flush();

} catch (IOException e) {

e.printStackTrace();

}finally{

try {

writer.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

public Vector readFile(){

FileReader reader=null;

BufferedReader br =null;

try {

reader = new FileReader(path);

br = new BufferedReader(reader);

String context= null;

Vector vec = new Vector();

while((context = br.readLine())!=null){

if(!"".equals(context)){

Vector user = new Vector();

user.add(context.substring(context.indexOf('=')+1,context.indexOf(';')));

user.add(context.substring(context.lastIndexOf('=')+1));

vec.add(user);

}

}

return vec;

} catch (FileNotFoundException e) {

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

finally{

try {

br.close();

reader.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

return null;

}

}

Java封装一个方法,求一个行列数相同的二维数组两条对角线所有元素的和。要产生随机数,键盘输入几行几列

先来分析一下思路,从键盘输入和获取随机数,都很容易,关键点就在怎样获取对角线。假设从键盘输入的数是n,总共生成n行n列的整数,遍历n行n列,要加的数就是第i行第i列,还有第i行第n-i+1列。其中,如果i=n-i+1,则这一行只加n,不用加n-i+1了,就是说,当i等于(n-1)/2时,这一行只加一次即可。

import java.util.Scanner;

import java.util.Random;

public static void main(String[] args) {

Random rd = new Random();

int result=0;

Scanner scan = new Scanner();

System.out.println("请输入行数:");

Int n = scan.nextInt();

int arr[][]=new int[n][n];

for(int i=0;in;i++){

for(int j=0;jn;j++){

arr[i][j]=rd.nextInt(100);

}

}

for(int k=0;karr.length;k++){

for(int l=0;larr[k].length;l++){

result+=arr[k][l];

if(k!=n-k+1){

result+=arr[k][l];

}

}

}

System.out.println(result);

}

java表格代码怎么写

java表格就是java swing。

//创建表头

String[] columnNames = { "First Name", "Last Name", "Sport",

"# of Years", "Vegetarian" };

//创建显示数据

Object[][] data = {

{ "Kathy", "Smith", "Snowboarding", new Integer(5),

new Boolean(false) },

{ "John", "Doe", "Rowing", new Integer(3), new Boolean(true) },

{ "Sue", "Black", "Knitting", new Integer(2),

new Boolean(false) },

{ "Jane", "White", "Speed reading", new Integer(20),

new Boolean(true) },

{ "Joe", "Brown", "Pool", new Integer(10), new Boolean(false) } };

/*

* JTable还提供了一个重载的构造方法,传入两个Vector

* JTable(Vector rowData, Vector columnNames)

*

*/

final JTable table = new JTable(data, columnNames);

table.setBackground(Color.YELLOW);

java的二维数组,,请看下面的代码,总成绩怎么出不来了呀

我把你的程序改了一下,成绩能出来了,你在我注释//设置表格中人员姓名及各科成绩 的循环中设置成绩。你还应该在程序中设置一下什么时候允许点击哪个按钮,否则很容易就抛出异常的。

public class Aaa extends JFrame implements ActionListener {

JTable table;

Object[][] a;

Object[] name = { "姓名", "英语", "数学", "总成绩", };

JButton button1, button2;

JTextField inputNumber;

int rows = 1;

JPanel p;

Aaa() {

a = new Object[rows][4];

init(a);

setBounds(550, 200, 550, 200);

//setSize(550,200);

setVisible(true);

setDefaultCloseOperation(EXIT_ON_CLOSE);

}

void init(Object[][] a) {

button2 = new JButton("计算总成绩");

button1 = new JButton("确定");

inputNumber = new JTextField(10);

button1.addActionListener(this);

button2.addActionListener(this);

table = new JTable(a, name);

p = new JPanel();

p.add(new JLabel("输入表格行数"));

p.add(inputNumber);

p.add(button2);

p.add(button1);

add(p, BorderLayout.SOUTH);

add(new JScrollPane(table), BorderLayout.CENTER);

}

public void actionPerformed(ActionEvent e) {

if (e.getSource() == button1) {

String temp = inputNumber.getText();

temp = temp==null || "".equals(temp) ? "0" : temp;

rows = Integer.parseInt(temp);

a = new Object[rows][4];

//设置表格中人员姓名及各科成绩

for (int i = 0; i a.length; i++) {

for (int j = 0; j a[i].length; j++) {

if(j==0){

a[i][j] = "aaa";

}else if(j==a[0].length-1){

a[i][j]=0;

}else{

a[i][j]=65;

}

}

}

table = new JTable(a, name);

getContentPane().removeAll();

init(a);

validate();

setVisible(true);

setDefaultCloseOperation(EXIT_ON_CLOSE);

}

if (e.getSource() == button2) {

for (int i = 0; i rows; i++) {

int sum = 0;

//boolean boo=true;

for (int j = 1; j a[i].length-1; j++) {

sum = sum + Integer.parseInt(a[i][j].toString());

//boo=false;

table.repaint();

//if(boo=true){

a[i][3] = "" + sum;

table.repaint();

}

}

}

}

public static void main(String[]args){

Aaa win=new Aaa();

win.setTitle("表格");

}

}

求一段java读取excel的程序,读为一个二维数组,excel中有许多空格,也要保留,或者用什么特殊数字代替

先看代码,挨句解释:

一般遍历使用两种方式,1:得到总的行数和每行的列数,然后循环。2:使用迭代

先看第一种:

Java代码

package com.golden.test;

import java.io.File;

import java.io.FileInputStream;

import org.apache.poi.hssf.usermodel.HSSFCell;

import org.apache.poi.hssf.usermodel.HSSFRow;

import org.apache.poi.hssf.usermodel.HSSFSheet;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;

/**

*

* @author 崔素强

*

*/

public class PoiReadXls2 {

public static void main(String[] args) {

File f = new File("c:\\a.xls");

try {

FileInputStream is = new FileInputStream(f);

HSSFWorkbook wbs = new HSSFWorkbook(is);

HSSFSheet childSheet = wbs.getSheetAt(0);

// System.out.println(childSheet.getPhysicalNumberOfRows());

System.out.println("有行数" + childSheet.getLastRowNum());

for (int j = 0; j childSheet.getLastRowNum(); j++) {

HSSFRow row = childSheet.getRow(j);

// System.out.println(row.getPhysicalNumberOfCells());

// System.out.println("有列数" + row.getLastCellNum());

if (null != row) {

for (int k = 0; k row.getLastCellNum(); k++) {

HSSFCell cell = row.getCell(k);

if (null != cell) {

switch (cell.getCellType()) {

case HSSFCell.CELL_TYPE_NUMERIC: // 数字

System.out.print(cell.getNumericCellValue()

+ " ");

break;

case HSSFCell.CELL_TYPE_STRING: // 字符串

System.out.print(cell.getStringCellValue()

+ " ");

break;

case HSSFCell.CELL_TYPE_BOOLEAN: // Boolean

System.out.println(cell.getBooleanCellValue()

+ " ");

break;

case HSSFCell.CELL_TYPE_FORMULA: // 公式

System.out.print(cell.getCellFormula() + " ");

break;

case HSSFCell.CELL_TYPE_BLANK: // 空值

System.out.println(" ");

break;

case HSSFCell.CELL_TYPE_ERROR: // 故障

System.out.println(" ");

break;

default:

System.out.print("未知类型 ");

break;

}

} else {

System.out.print("- ");

}

}

}

System.out.println();

}

} catch (Exception e) {

e.printStackTrace();

}

}

}

得到Excel的文件然后读取,这个很简单。关键有两个地方,也许在网上会看到有的这样使用有的那样使用。

System.out.println("有行数" + childSheet.getLastRowNum());

System.out.println(childSheet.getPhysicalNumberOfRows());

System.out.println("有列数" + row.getLastCellNum());

System.out.println(row.getPhysicalNumberOfCells());

如果人都拷贝代码进行使用了,不知道有什么区别。太多的区别不知道,但是有一点我发现了,那就是如果中间各行或者隔列的话getPhysicalNumberOfRows和getPhysicalNumberOfCells就不能读取到所有的行和列了。

再者,一定要对单元格的格式进行判断switch (cell.getCellType()),不同的单元格格式使用不同的方法。最后加上为止类型,以防万一。

而且在数字类型里,又分为了纯数字和时间格式:

Java代码

case HSSFCell.CELL_TYPE_NUMERIC: // 数值型

if (HSSFDateUtil.isCellDateFormatted(cell)) {

// 如果是date类型则 ,获取该cell的date值

value = HSSFDateUtil.getJavaDate(cell.getNumericCellValue()).toString();

} else { // 纯数字

value = String.valueOf(cell.getNumericCellValue());

}

还有一种迭代的方法:

Java代码

package com.golden.test;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.util.Iterator;

import org.apache.poi.hssf.usermodel.HSSFCell;

import org.apache.poi.hssf.usermodel.HSSFRow;

import org.apache.poi.hssf.usermodel.HSSFSheet;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;

import org.apache.poi.poifs.filesystem.POIFSFileSystem;

/**

*

* @author 崔素强

*

*/

public class PoiReadXls {

@SuppressWarnings( { "unchecked", "deprecation" })

public static void main(String[] args) {

File f = new File("c:\\a.xls");

try {

InputStream input = new FileInputStream(f);

POIFSFileSystem fs = new POIFSFileSystem(input);

HSSFWorkbook wb = new HSSFWorkbook(fs);

HSSFSheet sheet = wb.getSheetAt(0);

Iterator rows = sheet.rowIterator();

while (rows.hasNext()) {

HSSFRow row = (HSSFRow) rows.next();

// System.out.print("行:" + row.getRowNum() + " ");

Iterator cells = row.cellIterator();

while (cells.hasNext()) {

HSSFCell cell = (HSSFCell) cells.next();

// System.out.println("列:" + cell.getCellNum());

switch (cell.getCellType()) {

case HSSFCell.CELL_TYPE_NUMERIC: // 数字

System.out.print(cell.getNumericCellValue() + " ");

break;

case HSSFCell.CELL_TYPE_STRING: // 字符串

System.out.print(cell.getStringCellValue() + " ");

break;

case HSSFCell.CELL_TYPE_BOOLEAN: // Boolean

System.out.println(cell.getBooleanCellValue() + " ");

break;

case HSSFCell.CELL_TYPE_FORMULA: // 公式

System.out.print(cell.getCellFormula() + " ");

break;

case HSSFCell.CELL_TYPE_BLANK: // 空值

System.out.println(" ");

break;

case HSSFCell.CELL_TYPE_ERROR: // 故障

System.out.println(" ");

break;

default:

System.out.print("未知类型 ");

break;

}

}

System.out.println();

}

} catch (IOException ex) {

ex.printStackTrace();

}

}

}

这种方法,如果数据的紧凑的,使用还是方便的,但是我发现,如果是空行或者是空列,他就会隔过去。具体的自己试试就知道了。

另外,也能看到这里得到Excel文件的方式是通过File,如果要引用到Struts2里,这是很简单的,因为Struts2上传时Action里定义的就是File或者File数组。


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