java基础以及操作Excle

今天把会经常用的几个集合的迭代方法又练习了一下，放在这里，经常复习！

map集合迭代

/*** 迭代map【1】*/

for (Integer key : map.keySet()) {//迭代key值
for (String value : map.values()) {//跌打value值
System.out.println("迭代map【1】" + key + ":" + value);
}
//  System.out.println("key\t"+key);
}

/*** 迭代map【2】*/

for (Map.Entry<Integer, String> entry : map.entrySet()) {
　　System.out.println("迭代map【2】" + entry.getKey() + "：" + entry.getValue());
}

/*** 迭代map【3】*/

Iterator<Map.Entry<Integer, String>> entries = map.entrySet().iterator();
　　 while (entries.hasNext()) {
　　　　Map.Entry<Integer, String> entry = entries.next();
　　　　System.out.println("迭代map【3】" + entry.getKey() + "：" + entry.getValue());
}

List集合迭代

List list = new ArrayList();
list.add("1");
list.add("2");
list.add("3");
list.add("4");
int size = list.size();
System.out.println(size);
for(Object li:list){
System.out.println("foreach迭代List集合\t\t"+li);
}

Iterator iterator = list.iterator();
while (iterator.hasNext()){
System.out.println("Iterator迭代List集合\t\t"+iterator.next());
}

工作需要，经常需要操作本地的Excle,下面总结了一下创建Excle

JAVA EXCEL API:是一开放源码项目，通过它Java开发人员可以读取Excel文件的内容、创建新的Excel文件、更新已经存在的Excel文件。使用该API非Windows操作系统也可以通过纯Java应用来处理Excel数据表。因为它是使用Java编写的，所以我们在Web应用中可以通过JSP、Servlet来调用API实现对Excel数据表的访问。

package yh.com.excle;

import jxl.Workbook;
import jxl.format.*;
import jxl.format.Alignment;
import jxl.write.*;
import jxl.write.Colour;
import jxl.write.biff.RowsExceededException;

import java.io.File;
import java.io.IOException;

/**
* Created by vincce on 2015/11/9.
*/
public class WriteMsgToExcle {

private static final String  filePath = "E:\\study\\test\\createExcle.xls";

public static void main(String[] args) {
createExcle();
}

/**
* 创建Excle到本地
*/
public static void createExcle(){

try {
WritableWorkbook writableWorkbook = Workbook.createWorkbook(new File(filePath));//在指定目录下创建Excl
WritableSheet sheet = writableWorkbook.createSheet("myFirst", 0);//创建一个sheet ，参数含义分别是 sheet名字 该Excle文件中第一个sheet
sheet.setRowView(0, 600, false);//设置第一行的高度

WritableCellFormat writableCellFormat = new WritableCellFormat();
writableCellFormat.setBackground(Colour.GRAY_25);//设置背景色
writableCellFormat.setAlignment(Alignment.CENTRE);//设置居中显示

WritableFont color = new WritableFont(WritableFont.ARIAL);//选择字体
color.setColour(Colour.GOLD);//设置字体颜色为金黄色
WritableCellFormat colorFormat = new WritableCellFormat(color);

//第一行
//            Label l1 = new Label(0,0,"name",colorFormat);//创建单元格 参数含义分别是 列坐标，行坐标 内容,字体颜色
Label l1 = new Label(0,0,"name",writableCellFormat);//创建单元格 参数含义分别是 列坐标，行坐标 内容，背景色
sheet.addCell(l1);
//            Label l2 = new Label(1,0,"sex",colorFormat);
Label l2 = new Label(1,0,"sex",writableCellFormat);
sheet.addCell(l2);
//            Label l3 = new Label(2,0,"age",colorFormat);
Label l3 = new Label(2,0,"age",writableCellFormat);
sheet.addCell(l3);
//            Label l4 = new Label(3,0,"score",colorFormat);
Label l4 = new Label(3,0,"score",writableCellFormat);
sheet.addCell(l4);

//第二行
Label l5 = new Label(0,1,"john");
sheet.addCell(l5);
Label l6 = new Label(1,1,"male");
sheet.addCell(l6);
Label l7 = new Label(2,1,"20");
sheet.addCell(l7);
Label l8 = new Label(3,1,"100");
sheet.addCell(l8);

//将创建的内容写入到输出流，并关闭输出流
writableWorkbook.write();
writableWorkbook.close();

} catch (IOException e) {
e.printStackTrace();
} catch (RowsExceededException e) {
e.printStackTrace();
} catch (WriteException e) {
e.printStackTrace();
}

}
}

需要依赖

<dependency>
<groupId>net.sourceforge.jexcelapi</groupId>
<artifactId>jxl</artifactId>
<version>2.6.10</version>
</dependency>

读取Excle中的某一列

public static void test2(String path){
File file = new File(path);
Workbook workbook;
try {
workbook = Workbook.getWorkbook(file);
Sheet sheet = workbook.getSheet(0);//获取第一个sheet
Cell[] cell = sheet.getColumn(4);//获取第一列中的值
int len = cell.length;//共有多少行
Map<Integer,String> map = new HashMap();
for(int i = 0;i<len;i++){
Cell cell1 = cell[i];
System.out.println("第"+(i+Integer.parseInt("1"))+"行\t"+cell1.getContents()+"\t"+"'"+cell1.getContents()+"',");
map.put(i,cell1.getContents());
//                System.out.println("select * from axa_user where id="+"'"+cell1.getContents()+"',");
}
System.out.println("总共有"+len+"行");
System.out.println(map.toString());

/*
Sheet sheet1 = workbook.getSheet(1);//读取第二个sheet中的内容

Cell[] cell1 = sheet1.getColumn(0);//获取第一列中内容
Cell[] cell2 = sheet1.getColumn(1);//获取第二列中内容

Map<Integer,String> map1 = new HashMap<Integer, String>();
for(int len1=0;len1<cell1.length;len1++){
Cell c1 = cell1[len1];
map1.put(len1,c1.getContents());
}

Map<Integer,String> map2 = new HashMap<Integer, String>();
for(int len2=0;len2<cell2.length;len2++){
Cell c2 = cell2[len2];
map2.put(len2,c2.getContents());
}

Map<Integer,String> map3 = new HashMap<Integer, String>();

for(Map.Entry<Integer,String> entry2:map2.entrySet()){
for(Map.Entry<Integer,String> entry1:map1.entrySet()){
if(entry2.getValue().equals(entry1.getValue())){
map3.put(entry1.getKey(),entry1.getValue());
}
}
}

System.out.println(cell1.length);
System.out.println(cell2.length);
System.out.println("map1\t"+map1.toString());
System.out.println("map2\t"+map2.toString());
System.out.println("map3\t"+map3.toString());
*/

} catch (IOException e) {
e.printStackTrace();
} catch (BiffException e) {
e.printStackTrace();
}
}