lombok的使用

1、@NonNull 非空检验可以用@notNull代替，后者还可以有返回信息

1 @NotNull(message = "参数不能为null")
2     private boolean name;
3     @NonNull
4     private int age;

2、@Cleanup---这个在jdk1.7之后，可以用try with resourse

释放资源

1 public void test(){
2         try {
3             @Cleanup OutputStream outputStream = new FileOutputStream("");
4             outputStream.write(5);
5         } catch (Exception e) {
6             e.printStackTrace();
7         }
8     }

反编译后

 1 public void test() {
 2         try {
 3             FileOutputStream e = new FileOutputStream("");
 4 
 5             try {
 6                 e.write(5);
 7             } finally {
 8                 if(Collections.singletonList(e).get(0) != null) {
 9                     e.close();
10                 }
11 
12             }
13         } catch (Exception var6) {
14             var6.printStackTrace();
15         }
16 
17     }

try-with-resourse

1 public void test(){
2         try (OutputStream outputStream = new FileOutputStream("")){
3             outputStream.write(5);
4         } catch (Exception e) {
5             e.printStackTrace();
6         }
7     }

反编译后

 1 public void test() {
 2         try {
 3             FileOutputStream e = new FileOutputStream("");
 4             Throwable var2 = null;
 5 
 6             try {
 7                 e.write(5);
 8             } catch (Throwable var12) {
 9                 var2 = var12;
10                 throw var12;
11             } finally {
12                 if(e != null) {
13                     if(var2 != null) {
14                         try {
15                             e.close();
16                         } catch (Throwable var11) {
17                             var2.addSuppressed(var11);
18                         }
19                     } else {
20                         e.close();
21                     }
22                 }
23 
24             }
25         } catch (Exception var14) {
26             var14.printStackTrace();
27         }
28 
29     }

3、@getter--@setter---@Accessors

chain属性，可以想jq一样连续编程(默认是false)

 1 @Getter
 2 @Setter
 3 @Accessors(chain = true)
 4 public class TestDTO {
 5 
 6     private String name;
 7 
 8     private int age;
 9 
10 }

 1 public class TestDTO {
 2     private String name;
 3     private int age;
 4 
 5     public TestDTO() {
 6     }
 7 
 8     public String getName() {
 9         return this.name;
10     }
11 
12     public int getAge() {
13         return this.age;
14     }
15 
16     public TestDTO setName(String name) {
17         this.name = name;
18         return this;
19     }
20 
21     public TestDTO setAge(int age) {
22         this.age = age;
23         return this;
24     }
25 }

4、@ToString

1 @ToString
2 public class TestDTO {
3 
4     private String name;
5 
6     private int age;
7 
8 }

反编译

 1 public class TestDTO {
 2     private String name;
 3     private int age;
 4 
 5     public TestDTO() {
 6     }
 7 
 8     public String toString() {
 9         return "TestDTO(name=" + this.name + ", age=" + this.age + ")";
10     }
11 }

ToString里面的属性 includeFieldNames = false

1 @ToString(includeFieldNames = false)
2 public class TestDTO {
3 
4     private String name;
5 
6     private int age;
7 
8 }

反编译后--没有字段的名称

 1 public class TestDTO {
 2     private String name;
 3     private int age;
 4 
 5     public TestDTO() {
 6     }
 7 
 8     public String toString() {
 9         return "TestDTO(" + this.name + ", " + this.age + ")";
10     }
11 }

第二个属性

1 @ToString(exclude = "age")
2 public class TestDTO {
3 
4     private String name;
5 
6     private int age;
7 
8 }

反编译后--排除了exclude指定的属性

 1 public class TestDTO {
 2     private String name;
 3     private int age;
 4 
 5     public TestDTO() {
 6     }
 7 
 8     public String toString() {
 9         return "TestDTO(name=" + this.name + ")";
10     }
11 }

第三个属性

1 @ToString(of = "age")
2 public class TestDTO {
3 
4     private String name;
5 
6     private int age;
7 
8 }

反编译后--只出现了of = "age" 中的属性

 1 public class TestDTO {
 2     private String name;
 3     private int age;
 4 
 5     public TestDTO() {
 6     }
 7 
 8     public String toString() {
 9         return "TestDTO(age=" + this.age + ")";
10     }
11 }

第四个属性

1 @ToString(callSuper =true )
2 public class TestDTO {
3 
4     private String name;
5 
6     private int age;
7 
8 }

反编译后--输出了父类的toString

 1 public class TestDTO {
 2     private String name;
 3     private int age;
 4 
 5     public TestDTO() {
 6     }
 7 
 8     public String toString() {
 9         return "TestDTO(super=" + super.toString() + ", name=" + this.name + ", age=" + this.age + ")";
10     }
11 }

第五个属性

1 @ToString
2 @Getter
3 public class TestDTO {
4 
5     private String name;
6 
7     private int age;
8 
9 }

反编译后--使用了有@getter注解后使用了get方法

 1 public class TestDTO {
 2     private String name;
 3     private int age;
 4 
 5     public TestDTO() {
 6     }
 7 
 8     public String toString() {
 9         return "TestDTO(name=" + this.getName() + ", age=" + this.getAge() + ")";
10     }
11 
12     public String getName() {
13         return this.name;
14     }
15 
16     public int getAge() {
17         return this.age;
18     }
19 }

使用属性

1 @ToString(doNotUseGetters = true)
2 @Getter
3 public class TestDTO {
4 
5     private String name;
6 
7     private int age;
8 
9 }

反编译后--- (doNotUseGetters = true)--没有使用get方法，而是直接使用this.属性

 1 public class TestDTO {
 2     private String name;
 3     private int age;
 4 
 5     public TestDTO() {
 6     }
 7 
 8     public String toString() {
 9         return "TestDTO(name=" + this.name + ", age=" + this.age + ")";
10     }
11 
12     public String getName() {
13         return this.name;
14     }
15 
16     public int getAge() {
17         return this.age;
18     }
19 }

5、@EqualsAndHashCode

1 @EqualsAndHashCode
2 public class TestDTO {
3 
4     private String name;
5 
6     private int age;
7 
8 }

反编译后

 1 public class TestDTO {
 2     private String name;
 3     private int age;
 4 
 5     public TestDTO() {
 6     }
 7 
 8     public boolean equals(Object o) {
 9         if(o == this) {
10             return true;
11         } else if(!(o instanceof TestDTO)) {
12             return false;
13         } else {
14             TestDTO other = (TestDTO)o;
15             if(!other.canEqual(this)) {
16                 return false;
17             } else {
18                 String this$name = this.name;
19                 String other$name = other.name;
20                 if(this$name == null) {
21                     if(other$name == null) {
22                         return this.age == other.age;
23                     }
24                 } else if(this$name.equals(other$name)) {
25                     return this.age == other.age;
26                 }
27 
28                 return false;
29             }
30         }
31     }
32 
33     protected boolean canEqual(Object other) {
34         return other instanceof TestDTO;
35     }
36 
37     public int hashCode() {
38         boolean PRIME = true;
39         byte result = 1;
40         String $name = this.name;
41         int result1 = result * 59 + ($name == null?43:$name.hashCode());
42         result1 = result1 * 59 + this.age;
43         return result1;
44     }
45 }