我想要一个方法从Java中的URL参数中提取有时可能包含“&和=”的值

Question

package com.bml.icbs.ws.param;    
import java.util.HashMap;

公共类RequestParameter{

private String param;
private HashMap<String, String> hashmap;

    public RequestParameter(String param){

    this.param=param;
    this.hashmap = new HashMap<String, String>();

    Integer i; 
    String key,value;
    String myArray[] = this.param.split("&");


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

        key=myArray[i].substring(0,myArray[i].indexOf("="));
        value=myArray[i].substring(myArray[i].indexOf("=")+1);
        this.hashmap.put(key,value);
    }
}

public String getParameterValue(String key){
    return this.hashmap.get(key);
}

public String getParam() {
    return param;
}

public void setParam(String param) {
    this.param = param;
}

public HashMap<String, String> getHashmap() {
    return hashmap;
}

public void setHashmap(HashMap<String, String> hashmap) {

    this.hashmap = hashmap;
}

}

当我测试上述方法时，如果URL是“param2=ffffhhh&param1=oooo&param3=ppp&param4=iiii&param5=kkkkk”

  public static void main(String[] args) {
    RequestParameter reqParam = new RequestParameter("param2=ffffhhh&param1=oooo&param3=pppp&param4=iiii&param5=kkkkk");
    System.out.println("SIZE " + reqParam.getHashmap().size());
    System.out.println("URL " + reqParam.getParam());
    System.out.println("HASHMAP " + reqParam.getHashmap());
    System.out.println("PARAM1 = " reqParam.getParameterValue("param1"));

}

public static void main(String[] args) {
    RequestParameter reqParam = new RequestParameter("param2=ffff&&&hhh=&param1=oooo=&&param3=pppp&param4=iiii&&yy=&param5=kkkkk");
    System.out.println("SIZE " + reqParam.getHashmap().size());
    System.out.println("URL " + reqParam.getParam());
    System.out.println("HASHMAP " + reqParam.getHashmap());
    System.out.println("PARAM1 = " reqParam.getParameterValue("param1"));

}

它引发以下异常：线程“main”java.lang.StringIndexOutOfboundsException：String索引超出范围：在com.bml.icbs.ws.param.requestParameter处的java.lang.String.substring处的-1(String.java:1937)处的com.bml.icbs.ws.param.requestParameter.java:188)处的com.bml.icbs.ws.param.main.main(main.java:9)处的

Answer 1

确保数组元素！empy。

for (i=0;i<myArray.length;i++){
        if(myArray[i] == null || myArray[i].length()==0){
                continue;
        }
        key=myArray[i].substring(0,myArray[i].indexOf("="));
        value=myArray[i].substring(myArray[i].indexOf("=")+1);
        this.hashmap.put(key,value);
    }