我正在尝试从 JAVA 中的 MultiMap(org.apache.commons.collections.MultiMap) 中删除单个值

Question

我正在尝试从 Java 中的 MultiMap (org.apache.commons.collections.MultiMap) 中删除单个值。问题是它包含两个值。当我删除一个时，另一个也会被删除。

class MappedValue
{
  public MappedValue(String id , boolean touched) {
    identifier = id;
    this.touched=touched;
  }

  private String  identifier;  
  private boolean touched; 
}   

MultiMap SuccessorsArray = new MultiValueMap();   

MappedValue mv = new MappedValue("1", false);
MappedValue mv2 = new MappedValue("2", true);

SuccessorsArray.put("key1", mv );         
SuccessorsArray.put("key1", mv2 );      
//Below is the problem as both values in the get removed instead of 1(mv).
SuccessorsArray.remove("key1", mv);

Answer 1

请试试这个

MultiValueMap SuccessorsArray = new MultiValueMap();

而不是

MultiMap SuccessorsArray = new MultiValueMap();

我用 commons-collection 的 3.2.1 版本测试过，它可以工作。

顺便说一句，您不应该将地图命名为 SuccessorsArray，而应命名为 successorsArray。

Answer 2

我刚刚测试了 3.2.1 版本并且

public static void main(String[] args) {
    class MappedValue {
        public MappedValue(String id, boolean touched) {
            identifier = id;
            this.touched = touched;
        }
        private String identifier;
        private boolean touched;
        @Override
        public String toString() {
            return "MappedValue [identifier=" + identifier + ", touched=" + touched + "]";
        }
    }

    MultiMap multiMap = new MultiValueMap();
    MappedValue mv = new MappedValue("1", false);
    MappedValue mv2 = new MappedValue("2", true);
    multiMap.put("key1", mv);
    multiMap.put("key1", mv2);
    //Below is the problem as both values in the get removed instead of 1(mv).
    multiMap.remove("key1", mv);
    System.out.println(multiMap.get("key1"));
}

returns [MappedValue [identifier=2, touched=true]]

所以该值确实没有被删除。

我正在尝试从 JAVA 中的 MultiMap(org.apache.commons.collections.MultiMap) 中删除单个值

I am trying to remove a single value from a MultiMap(org.apache.commons.collections.MultiMap) in JAVA

java

collections

graph

hashmap