Java代码实现对properties文件有序的读写的示例

package com.lxk.propertyFileTest;  import java.util.*;   public class OrderedProperties extends Properties {   private static final long serialVersionUID = -4627607243846121965L;       private final LinkedHashSet<Object> keys = new LinkedHashSet<>();    @Override   public Enumeration<Object> keys() {     return Collections.enumeration(keys);   }       @Override   public Object put(Object key, Object value) {     keys.add(key);     return super.put(key, value);   }       @Override   public Set<String> stringPropertyNames() {     Set<String> set = new LinkedHashSet<>();     for (Object key : this.keys) {       set.add((String) key);     }     return set;   }       @Override   public Set<Object> keySet() {     return keys;   }    //这个就不设置有序了，因为涉及到HashTable内部类：EntrySet，不好复写。   //public LinkedHashSet<Map.Entry<Object, Object>> entrySet() {   //  LinkedHashSet<Map.Entry<Object, Object>> entrySet = new LinkedHashSet<>();   //  for (Object key : keys) {   //   //  }   //  return entrySet;   //}       @Override   public Enumeration<?> propertyNames() {     return Collections.enumeration(keys);   } }