java将list转换为字符串_List转换成String字符串三种方式
List转换成String字符串思路分析： 1.List转化成String[],再通过String[]数组遍历拼接成String字符串; 2.List转化成String存到StringBuffer中,再通过StringButter中的append()方法拼接成String字符串; 注意：StringBuffer字符串变量、StringBuilder字符串变量在方式二和方式三种可以把StringBuffer换成StringBuilder，但需要了解二者之间的区别，网址：https://blog.csdn.net/u013131716/article/details/99628104
package com.test01.listtostring;
import java.util.ArrayList;
import java.util.List;
import org.junit.Test;
public class ListToStringTest {
/*
* List转换成String字符串
* 方式一：
* 分析：List转化成String[],再通过String[]数组遍历拼接成String字符串
*
* List内容：[laoyi, laoer, laosan]
* 结果：laoyi,laoer,laosan
* */
@SuppressWarnings({ "rawtypes", "unchecked", "unused" })
@Test
public void listToString01(){
List list = new ArrayList<>();
list.add("laoyi");
list.add("laoer");
list.add("laosan");
System.out.println("List数组："+list);
if(list == null && list.size() == 0){
System.out.println("list中的内容为空！");
}else{
String[] strArrStrings = new String[list.size()];
String resultString = "";
for(int i=0;i<=list.size()-1;i++){
strArrStrings[i] = (String) list.get(i);
}
for(int j=0;j<=strArrStrings.length-1;j++){
if(j < strArrStrings.length-1){
resultString += strArrStrings[j] + ",";
}else{
resultString += strArrStrings[j];
}
}
System.out.println("最后拼接的字符串：" + resultString);
}
}
/*
* List转换成String字符串
* 方式二：
* 分析：List转化成String存到StringBuilder中,再通过StringBuilder中的append()方法拼接成String字符串
*
* List内容：[laoyi, laoer, laosan]
* 结果：laoyi,laoer,laosan
* */
@SuppressWarnings({ "unused" })
@Test
public void listToString03(){
List list = new ArrayList<>();
list.add("laoyi");
list.add("laoer");
list.add("laosan");
if(null ==list && list.size()<=0){
System.out.println("list内容为空！");
}else{
StringBuilder sb = new StringBuilder();
String resultString = "";
for(int i=0;i
if(i
sb.append(list.get(i));
sb.append(",");
}else{
sb.append(list.get(i));
}
}
resultString = sb.toString();
System.out.println("最后拼接的字符串结果：" + resultString);
}
}
/*
* List转换成String字符串
* 方式三：
* 分析：List转化成String存到StringBuffer中,再通过StringButter中的append()方法拼接成String字符串
*
* List内容：[laoyi, laoer, laosan]
* 结果：laoyi,laoer,laosan
* */
@SuppressWarnings({ "unused" })
@Test
public void listToString02(){
List list = new ArrayList<>();
list.add("laoyi");
list.add("laoer");
list.add("laosan");
if(null ==list && list.size()<=0){
System.out.println("list内容为空！");
}else{
StringBuilder sb = new StringBuilder();
String resultString = "";
boolean flag = false;
for(String str : list){
if(flag){
sb.append(",");
}else{
flag = true;
}
sb.append(str);
}
resultString = sb.toString();
System.out.println("最后拼接的字符串结果：" + resultString);
}
}
}