Java + 集合 + TreeSet +定制排序

public class Customer{ private Integer id; private String name; public Integer getId(){ return id; } public void setId(Integer id){ this.id = id; } public void setName(String name){ this.name = name; } public String getName(){ return name; } public Customer(String name,Integer id){ super(); this.name = name; this.id = id; } public Customer(){ super(); } @Override public String toString(){ return "Customer [name= " + name + ", id=" + id + "]"; } @Override public int hashCode(){ final int prime = 31; int result = 1; result = prime * result + ((id == null) ? 0 : id.hashCode()); result = prime * result + ((name == null) ? 0 : name.hashCode()); return result; } @Override public boolean equals(Object obj){ if(this == obj) return true; if(obj == null) return false; if(getClass() != obj.getClass()) return false; Customer other = (Customer)obj; if(id == null){ if(other.id != null) return false; }else if(!id.equals(other.id)) return false; if(name == null){ if(other.name != null) return false; }else if(!name.equals(other.name)) return false; return true; } }