what's up in java 7

Java SE Development Kit 7.

1. 对集合的支持.

01.List<String> list =["item"];

02.String item = list[0];

03.Set<String> set ={"item"};

04.Map<String,Integer> map ={"key",1};

05.int value = map["key"];

2. 对资源的自动回收管理

BufferedReader br = new BufferedReader(new FileReader(path));

try{

return br.readLine();}

finally{br.close();}

in 7.0

try (BufferedReader br = new BuferedReader(new FileReader(path));){

return br.readLine();}

3.泛型实例创建过程中类型引用的简化:当声明你的对象的接口时,不需要重复指明泛型类型.

Map<String,String> hello = new Map<>();

4 .对字符串进行switch case

String availability = "available";

switch(availability){

case "available":

//code statement;

break;

case "unavailable":

// code statement;

break;

default:

// code statement;

break;}

7.0前case valueN : valueN的类型必须是与int类型兼容的基本类型,包括byte、short、char.

在7.0中把字符串传进switch case中 需要判断字符串是否为Null值.

5.一个catch里捕捉多个异常类型.

try{

//code statement;

}catch(IOException| NullPointerException|.....){}