Map的遍历方法及String和其它类型的相互转化

  • Map的遍历方法:

package com.lky.test;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

import org.junit.Test;

public class mapTest {
    
    public static String []keys=new String[]{"name","sex","email","phone"};
    public static String []values=new String[]{"lky","male","1411074230@qq.com","016515151"};
    public static Map<String,String> info=new HashMap<String,String>();
    static{
          for(int i=0;i<values.length;++i){
              info.put(keys[i], values[i]);
          }
    }
    
    
    @Test
    public void testMap(){
        for(Entry<String, String> entry:info.entrySet()){
            System.out.println(entry.getKey()+"---"+entry.getValue());
        }
        System.out.println("---------------");
    }
    
    @Test
    public void testMap1(){
        for(String key:info.keySet()){
            System.out.println(key+"--------"+info.get(key));
        }
        System.out.println("---------------");
    }
    
    @Test
    public void testMap2(){
        Iterator<Entry<String, String>> iterator=info.entrySet().iterator();
        while(iterator.hasNext()){
            Entry<String, String> s=iterator.next();
            System.out.println(s.getKey()+"----------"+s.getValue());
        }
    }
}
  • String和其它数据类型的相互转化

package com.lky.test;

import java.io.UnsupportedEncodingException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.junit.Test;

public class stringToElse {
    
    //字符串和byte数组之间的转化
    @Test
    public void test() throws UnsupportedEncodingException{
        String s="lky";
        byte[] info=s.getBytes();
        
        String s1=new String(info,"utf-8");
        System.out.println(s1);
    }
    
    //字符串和Date之间的转化
    @Test
    public void test1() throws ParseException{
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
        Date date=  sdf.parse("2015-10-14");//将字符串转化成Date类型
        System.out.println(date);
        
        System.out.println(sdf.format(date));//将日期类型转化成字符串类型
    }
    
    //字符串和int之间的转化
    @Test
    public void test2(){
        String s="1000";
        int integer=Integer.parseInt(s);
        System.out.println(integer);
        
        System.out.println(Integer.valueOf(integer).toString());
    }
    

}
原文地址:https://www.cnblogs.com/dmir/p/4878470.html