lombok使用手册：

1、安装插件

1.1、idel：

elipse:下载地址https://projectlombok.org/download

运行jar文件

1.2、使用lombok还需要引用相关jar包

参考网址：https://projectlombok.org/features/all

2、注解说明

2.1、@Data

@Data
All together now: A shortcut for @ToString, @EqualsAndHashCode, @Getter on all fields, and @Setter on all non-final fields, and @RequiredArgsConstructor!
Lombok代码：

@Data

public class Lombok {

    private String name;

    private String age;

}

编译后代码：

public class Lombok {

    private String name;

    private String age;

    public Lombok() {

    }

    public String getName() {

        return this.name;

    }

    public String getAge() {

        return this.age;

    }

    public void setName(String name) {

        this.name = name;

    }

    public void setAge(String age) {

        this.age = age;

    }

    public boolean equals(Object o) {

        if(o == this) {

            return true;

        } else if(!(o instanceof Lombok)) {

            return false;

        } else {

            Lombok other = (Lombok)o;

            if(!other.canEqual(this)) {

                return false;

            } else {

                String this$name = this.getName();

                String other$name = other.getName();

                if(this$name == null) {

                    if(other$name != null) {

                        return false;

                    }

                } else if(!this$name.equals(other$name)) {

                    return false;

                }

                String this$age = this.getAge();

                String other$age = other.getAge();

                if(this$age == null) {

                    if(other$age != null) {

                        return false;

                    }

                } else if(!this$age.equals(other$age)) {

                    return false;

                }

                return true;

            }

        }

    }

    protected boolean canEqual(Object other) {

        return other instanceof Lombok;

    }

    public int hashCode() {

        boolean PRIME = true;

        byte result = 1;

        String $name = this.getName();

        int result1 = result * 59 + ($name == null?43:$name.hashCode());

        String $age = this.getAge();

        result1 = result1 * 59 + ($age == null?43:$age.hashCode());

        return result1;

    }

    public String toString() {

        return "Lombok(name=" + this.getName() + ", age=" + this.getAge() + ")";

    }

}

2.2、@val

编译前代码：

    val example = new ArrayList<String>();

    example.add("Hello, World!");

    val foo = example.get(0);

    return foo.toLowerCase();

    val map = new HashMap<Integer, String>();

    map.put(0, "zero");

    map.put(5, "five");

    for (val entry : map.entrySet()) {

      System.out.printf("%d: %s\n", entry.getKey(), entry.getValue());

    }

编译后代码：

    final ArrayList<String> example = new ArrayList<String>();

    example.add("Hello, World!");

    final String foo = example.get(0);

    return foo.toLowerCase();

    final HashMap<Integer, String> map = new HashMap<Integer, String>();

    map.put(0, "zero");

    map.put(5, "five");

    for (final Map.Entry<Integer, String> entry : map.entrySet()) {

      System.out.printf("%d: %s\n", entry.getKey(), entry.getValue());

    }

2.3、@var 用法参考@val

2.4、@NonNull

编译前代码：

  public NonNullExample(@NonNull Person person) {

    this.name = person.getName();

  }

编译后代码：

public NonNullExample(@NonNull Person person) {

    if (person == null) {

      throw new NullPointerException("person is marked @NonNull but is null");

    }

    this.name = person.getName();

  }

2.5、@Cleanup

编译前代码：

    @Cleanup InputStream in = new FileInputStream(args[0]);

    @Cleanup OutputStream out = new FileOutputStream(args[1]);

    byte[] b = new byte[10000];

    while (true) {

      int r = in.read(b);

      if (r == -1) break;

      out.write(b, 0, r);

    }

编译后代码：

    InputStream in = new FileInputStream(args[0]);

    try {

      OutputStream out = new FileOutputStream(args[1]);

      try {

        byte[] b = new byte[10000];

        while (true) {

          int r = in.read(b);

          if (r == -1) break;

          out.write(b, 0, r);

        }

      } finally {

        if (out != null) {

          out.close();

        }

      }

    } finally {

      if (in != null) {

        in.close();

      }

    }

2.6、@Getter、@Setter

编译前代码：

  @Getter @Setter private int age = 10;

  @Setter private String name;

编译后代码：

  public int getAge() {

    return age;

  }

  public void setAge(int age) {

    this.age = age;

  }

  protected void setName(String name) {

    this.name = name;

  }

2.7、@ToString

编译前代码：

@ToString

public class Lombok {

    @Getter @Setter String name;

    @Getter @Setter private String age;

    @ToString.Exclude String id;

}

编译后代码：

public class Lombok {

    String name;

    private String age;

    String id;

    public Lombok() {

    }

    public String toString() {

        return "Lombok(name=" + this.getName() + ", age=" + this.getAge() + ")";

    }

    public String getName() {

        return this.name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getAge() {

        return this.age;

    }

    public void setAge(String age) {

        this.age = age;

    }

}

2.8、@EqualsAndHashCode

编译前代码：

@EqualsAndHashCode

public class Lombok {

    @Getter @Setter String name;

    @Getter @Setter private String age;

    @EqualsAndHashCode.Exclude String id;

}

编译后代码：

public class Lombok {

    String name;

    private String age;

    String id;

    public Lombok() {

    }

    public boolean equals(Object o) {

        if(o == this) {

            return true;

        } else if(!(o instanceof Lombok)) {

            return false;

        } else {

            Lombok other = (Lombok)o;

            if(!other.canEqual(this)) {

                return false;

            } else {

                String this$name = this.getName();

                String other$name = other.getName();

                if(this$name == null) {

                    if(other$name != null) {

                        return false;

                    }

                } else if(!this$name.equals(other$name)) {

                    return false;

                }

                String this$age = this.getAge();

                String other$age = other.getAge();

                if(this$age == null) {

                    if(other$age != null) {

                        return false;

                    }

                } else if(!this$age.equals(other$age)) {

                    return false;

                }

                return true;

            }

        }

    }

    protected boolean canEqual(Object other) {

        return other instanceof Lombok;

    }

    public int hashCode() {

        boolean PRIME = true;

        byte result = 1;

        String $name = this.getName();

        int result1 = result * 59 + ($name == null?43:$name.hashCode());

        String $age = this.getAge();

        result1 = result1 * 59 + ($age == null?43:$age.hashCode());

        return result1;

    }

    public String getName() {

        return this.name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getAge() {

        return this.age;

    }

    public void setAge(String age) {

        this.age = age;

    }

}

2.9、@NoArgsConstructor, @RequiredArgsConstructor, @AllArgsConstructor构造器

编译前代码：

@RequiredArgsConstructor(staticName = "of")

@AllArgsConstructor(access = AccessLevel.PROTECTED)

public class ConstructorExample<T> {

  private int x, y;

  @NonNull private T description;

  @NoArgsConstructor

  public static class NoArgsExample {

    @NonNull private String field;

  }

}

编译后代码：

 public class ConstructorExample<T> {

  private int x, y;

  @NonNull private T description;

  private ConstructorExample(T description) {

    if (description == null) throw new NullPointerException("description");

    this.description = description;

  }

  public static <T> ConstructorExample<T> of(T description) {

    return new ConstructorExample<T>(description);

  }

  @java.beans.ConstructorProperties({"x", "y", "description"})

  protected ConstructorExample(int x, int y, T description) {

    if (description == null) throw new NullPointerException("description");

    this.x = x;

    this.y = y;

    this.description = description;

  }

  public static class NoArgsExample {

    @NonNull private String field;

    public NoArgsExample() {

    }

  }

}

2.10、@Value用法参考@Data默认设置为final，会被其他注解显示生效

2.11、@Builder

编译前代码：

@Builder

public class BuilderExample {

    @Builder.Default private long created = System.currentTimeMillis();

    private String name;

    private int age;

    @Singular

    private Set<String> occupations;

}

编译后代码：

public class BuilderExample {

    private long created;

    private String name;

    private int age;

    private Set<String> occupations;

    private static long $default$created() {

        return System.currentTimeMillis();

    }

    BuilderExample(long created, String name, int age, Set<String> occupations) {

        this.created = created;

        this.name = name;

        this.age = age;

        this.occupations = occupations;

    }

    public static BuilderExample.BuilderExampleBuilder builder() {

        return new BuilderExample.BuilderExampleBuilder();

    }

    public static class BuilderExampleBuilder {

        private boolean created$set;

        private long created$value;

        private String name;

        private int age;

        private ArrayList<String> occupations;

        BuilderExampleBuilder() {

        }

        public BuilderExample.BuilderExampleBuilder created(long created) {

            this.created$value = created;

            this.created$set = true;

            return this;

        }

        public BuilderExample.BuilderExampleBuilder name(String name) {

            this.name = name;

            return this;

        }

        public BuilderExample.BuilderExampleBuilder age(int age) {

            this.age = age;

            return this;

        }

        public BuilderExample.BuilderExampleBuilder occupation(String occupation) {

            if(this.occupations == null) {

                this.occupations = new ArrayList();

            }

            this.occupations.add(occupation);

            return this;

        }

        public BuilderExample.BuilderExampleBuilder occupations(Collection<? extends String> occupations) {

            if(this.occupations == null) {

                this.occupations = new ArrayList();

            }

            this.occupations.addAll(occupations);

            return this;

        }

        public BuilderExample.BuilderExampleBuilder clearOccupations() {

            if(this.occupations != null) {

                this.occupations.clear();

            }

            return this;

        }

        public BuilderExample build() {

            Set occupations;

            switch(this.occupations == null?0:this.occupations.size()) {

            case 0:

                occupations = Collections.emptySet();

                break;

            case 1:

                occupations = Collections.singleton(this.occupations.get(0));

                break;

            default:

                LinkedHashSet occupations1 = new LinkedHashSet(this.occupations.size() < 1073741824?1 + this.occupations.size() + (this.occupations.size() - 3) / 3:2147483647);

                occupations1.addAll(this.occupations);

                occupations = Collections.unmodifiableSet(occupations1);

            }

            long created$value = this.created$value;

            if(!this.created$set) {

                created$value = System.currentTimeMillis();

            }

            return new BuilderExample(created$value, this.name, this.age, occupations);

        }

        public String toString() {

            return "BuilderExample.BuilderExampleBuilder(created$value=" + this.created$value + ", name=" + this.name + ", age=" + this.age + ", occupations=" + this.occupations + ")";

        }

    }

}

2.12、@SneakyThrows

编译前代码：

 @SneakyThrows(UnsupportedEncodingException.class)

  public String utf8ToString(byte[] bytes) {

    return new String(bytes, "UTF-8");

  }

  @SneakyThrows

  public void run() {

    throw new Throwable();

  }

编译后代码：

  public String utf8ToString(byte[] bytes) {

    try {

      return new String(bytes, "UTF-8");

    } catch (UnsupportedEncodingException e) {

      throw Lombok.sneakyThrow(e);

    }

  }

  public void run() {

    try {

      throw new Throwable();

    } catch (Throwable t) {

      throw Lombok.sneakyThrow(t);

    }

  }

2.13、@Synchronized

编译前代码：

public class SynchronizedExample {

  private final Object readLock = new Object();

  @Synchronized

  public static void hello() {

    System.out.println("world");

  }

  @Synchronized

  public int answerToLife() {

    return 42;

  }

  @Synchronized("readLock")

  public void foo() {

    System.out.println("bar");

  }

}

编译后代码：

 public class SynchronizedExample {

  private static final Object $LOCK = new Object[0];

  private final Object $lock = new Object[0];

  private final Object readLock = new Object();

  public static void hello() {

    synchronized($LOCK) {

      System.out.println("world");

    }

  }

  public int answerToLife() {

    synchronized($lock) {

      return 42;

    }

  }

  public void foo() {

    synchronized(readLock) {

      System.out.println("bar");

    }

  }

}

2.14、@With 必须要包含全参数构造器

编译前代码：

@AllArgsConstructor

public class Lombok {

    @With private Integer x;

    @With private Integer y;

    @With private Integer z;

}

编译后代码：

public class Lombok {

    private Integer x;

    private Integer y;

    private Integer z;

    public Lombok(Integer x, Integer y, Integer z) {

        this.x = x;

        this.y = y;

        this.z = z;

    }

    public Lombok withX(Integer x) {

        return this.x == x?this:new Lombok(x, this.y, this.z);

    }

    public Lombok withY(Integer y) {

        return this.y == y?this:new Lombok(this.x, y, this.z);

    }

    public Lombok withZ(Integer z) {

        return this.z == z?this:new Lombok(this.x, this.y, z);

    }

}

2.15、@Getter(lazy=true)缓存

编译前代码：

public class Lombok {

    @Getter(lazy=true) private final int[] cached = expensive();

    private int[] expensive() {

        int[] result = new int[1000000];

        for (int i = 0; i < result.length; i++) {

            result[i] = i;

        }

        return result;

    }

}

编译后代码：

public class Lombok {

    private final AtomicReference<Object> cached = new AtomicReference();

    public Lombok() {

    }

    private int[] expensive() {

        int[] result = new int[1000000];

        for(int i = 0; i < result.length; result[i] = i++) {

            ;

        }

        return result;

    }

    public int[] getCached() {

        Object value = this.cached.get();

        if(value == null) {

            AtomicReference var2 = this.cached;

            synchronized(this.cached) {

                value = this.cached.get();

                if(value == null) {

                    int[] actualValue = this.expensive();

                    value = actualValue == null?this.cached:actualValue;

                    this.cached.set(value);

                }

            }

        }

        return (int[])((int[])(value == this.cached?null:value));

    }

}

2.16、日志@Log (and friends)

@CommonsLog
    Creates private static final org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory.getLog(LogExample.class);
@Flogger
    Creates private static final com.google.common.flogger.FluentLogger log = com.google.common.flogger.FluentLogger.forEnclosingClass();
@JBossLog
    Creates private static final org.jboss.logging.Logger log = org.jboss.logging.Logger.getLogger(LogExample.class);
@Log
    Creates private static final java.util.logging.Logger log = java.util.logging.Logger.getLogger(LogExample.class.getName());
@Log4j
    Creates private static final org.apache.log4j.Logger log = org.apache.log4j.Logger.getLogger(LogExample.class);
@Log4j2
    Creates private static final org.apache.logging.log4j.Logger log = org.apache.logging.log4j.LogManager.getLogger(LogExample.class);
@Slf4j
    Creates private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(LogExample.class);
@XSlf4j
    Creates private static final org.slf4j.ext.XLogger log = org.slf4j.ext.XLoggerFactory.getXLogger(LogExample.class);
@CustomLog
    Creates private static final com.foo.your.Logger log = com.foo.your.LoggerFactory.createYourLogger(LogExample.class);

@Log

public class Lombok {

    @Getter(lazy=true) private final int[] cached = expensive();

    private int[] expensive() {

        int[] result = new int[1000000];

        for (int i = 0; i < result.length; i++) {

            result[i] = i;

        }

        log.severe(result.toString());

        return result;

    }

}

2.17、额外的注解见链接https://projectlombok.org/features/all

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