The use of JSON packages in Java and the conversion of strings, Map,list, and custom objects to each other

To do a map and string conversion, you need to import these jar packages, which are some of the most basic jar packages.

After multiple attempts to draw conclusions into:

First import the basic package: Json-lib-2.2.3-jdk15.jar

Without this jar package, the program is not writable.

Now it's guaranteed that the program will compile and run.

Exception occurred: org/apache/commons/lang/exception/nestableruntimeexception

Import Commons-lang-2.3.jar, problem solved.

Run for a moment:

Exception occurred: Java.lang.ClassNotFoundException:net.sf.ezmorph.Morpher

Import Ezmorph-1.0.3.jar, problem solving

Run for a moment:

Exception occurred: Java.lang.ClassNotFoundException:org.apache.commons.logging.LogFactory

Import Commons-logging-1.1.1.jar, problem solving

Run for a moment:

Exception occurred: Java.lang.noclassdeffounderror:org/apache/commons/collections/map/listorderedmap

Import Commons-collections-3.2.1.jar, problem solving

Run for a moment:

Exception occurred: Java.lang.noclassdeffounderror:org/apache/commons/beanutils/dynabean

Import Commons-beanutils-1.7.0.jar, problem solving

Run, the exception is gone.

Let's see how these things are converted.

Map Turn string

Map<string, string> map=new hashmap<string, string>(); Map.put ("name", "Dr. Sisi"); Map.put ("age", "+");
jsonobject jsonobject=jsonobject. Fromobject (map); String res=jsonobject. toString (); System.out.println (res);

Result: {"age": "+", "name": "Dr. Sisi"}

List Turn string

list<string> list=New arraylist<string>() list.add ("Zhonghua"); List.add ("name" ); List.add ("Republic");        Jsonarray Jsonarray=jsonarray.fromobject (list); String res=jsonarray.tostring (); System.out.println (res);

Results: ["China", "name", "Republic"]
String goto Map

String res= "{\" age\ ": \" 25\ ", \" name\ ": \" Sisi dr \ "}"; // or so // res= "{' Age ': ' + ', ' name ': ' Dr. Sisi '}"; Jsonobject jsonobject=Jsonobject.fromobject (res); Map<String,String> map = (hashmap<string,string>) Jsonobject.tobean (Jsonobject, HashMap.  Class); SYSTEM.OUT.PRINTLN (map); System.out.println (Map.size ()); System.out.println (Map.get ("name")); System.out.println (Map.getclass (). GetName ());

Results:

{Dr. Name= Sisi, age=25}
2
Dr. Sisi
Java.util.HashMap

String into our custom class

Userbean.java

 PackageJSON; Public classUserBean {PrivateString name; PrivateString age;  PublicString GetName () {returnname; }     Public voidsetName (String name) { This. Name =name; }     PublicString getage () {returnAge ; }     Public voidsetage (String age) { This. Age =Age ; } }

String UserS = "{' name ': ' Dr. Sisi ', ' age ': '+ ' == (UserBean) jsonobject.tobean (obj, UserBean.  Class); System.out.println (Userbean.getname ());

String converted to List

String arraystring= "[' A ', ' B ', ' CCC ']"; Jsonarray Jsonarray=jsonarray.fromobject (arraystring); object[] arr=jsonarray.toarray (); System.out.println (arr.length); System.out.println (arr[2]);

Results:

3
Ccc

The use of JSON packages in Java and the conversion of strings, Map,list, and custom objects to each other