详解Java中的final关键字的使用

final int constValue = 1;
// constValue = 2; The final local variable constValue cannot be assigned.

public class Person
{
  public final void printName() {
    System.out.println("wangzhengyi");
  }
}

import java.util.HashMap;
import java.util.Iterator;


public class FinalClassExample {
  private final int id;

  private final String name;

  private final HashMap<Integer, String> hMap;

  public int getId() {
    return id;
  }

  public String getName() {
    return name;
  }

  /**
   * 可变对象的访问方法：返回对象的拷贝
   * @return
   */
  public HashMap<Integer, String> gethMap() {
    return (HashMap<Integer, String>)hMap.clone();
  }

  /**
   * 实现深拷贝的构造器
   */
  public FinalClassExample(int id, String name, HashMap<Integer, String> map) {
    this.id = id;
    this.name = name;

    HashMap<Integer, String> tMap = new HashMap<Integer, String>();
    int key;
    Iterator<Integer> iterator = map.keySet().iterator();
    while (iterator.hasNext()) {
      key = iterator.next();
      tMap.put(key, map.get(key));
    }

    this.hMap = tMap;
  }

  /**
   * 实现浅拷贝构造器
   */
  /*
  public FinalClassExample(int id, String name, HashMap<Integer, String> map) {
    this.id = id;
    this.name = name;
    this.hMap = map;
  }
  */
}