Based on json-lib.jar package JSON program practice

Based on the json-lib.jar package JSON program, this article mainly introduces a simple example! 1. First, JSON-lib must support at least the following JAR packages Jakarta commons-lang 2.4 Jakarta commons-beanutils 1.7.0 Jakarta commons-collections 3.2 Jakarta commons-logging 1.1.1 Ezmorph 1.0.6 2. arrays of the Java Collection type. collections is converted to jsonarray. Example 1: Boolean [] boolarray = new Boolean [] {true, false, true }; Jsonarray = jsonarray. fromobject (boolarray ); System. Out. println (jsonarray ); Output: [true, false, true] Example 2: List list = new arraylist (); List. Add ("first "); List. Add ("second "); Jsonarray = jsonarray. fromobject (list ); System. Out. println (jsonarray ); Output: ["first", "second"] Example 3: Jsonarray = jsonarray. fromobject ("['json', 'is', 'easy']"); System. Out. println (jsonarray ); Output: ["JSON", "is", "easy"] 3. Conversion of Java object type JavaBean and maps with jsonobject Example 1: Map map = new hashmap (); Map. Put ("name", "JSON "); Map. Put ("bool", Boolean. True ); Map. Put ("int", new INTEGER (1 )); Map. Put ("arr", new string [] {"A", "B "}); Map. Put ("func", "function (I) {return this. Arr [I];}"); Jsonobject = jsonobject. fromobject (MAP ); System. Out. println (jsonobject ); Output: {"func": function (I) {return this. arr [I] ;}, "arr": ["A", "B"], "int": 1, "bool": True, "name ": "JSON "} Example 2: Class mybean { Private string name = "JSON "; Private int pojoid = 1; Private char [] Options = new char [] {'A', 'F '}; Private string func1 = "function (I) {return this. Options [I];}"; Private jsonfunction func2 = new jsonfunction (New String [] {"I"}, "return this. Options [I];"); // Getters & setters ... } Jsonobject = jsonobject. fromobject (New mybean ()); System. Out. println (jsonobject ); Output: {"func1": function (I) {return this. options [I];}, "func2": function (I) {return this. options [I];}, "name": "JSON", "options": ["A", "F"], "pojoid": 1} 4. Convert JSON Data Object format to Java type beans Example 1 (convert to dynamic bean ): String JSON = "{name = \" JSON \ ", bool: True, INT: 1, double: 2.2, FUNC: function (a) {return a ;}, array: [1, 2]} "; Jsonobject = jsonobject. fromobject (JSON ); Object bean = jsonobject. tobean (jsonobject ); Assertequals (jsonobject. Get ("name"), propertyutils. getproperty (bean, "name ")); Assertequals (jsonobject. Get ("bool"), propertyutils. getproperty (bean, "bool ")); Assertequals (jsonobject. Get ("int"), propertyutils. getproperty (bean, "int ")); Assertequals (jsonobject. Get ("double"), propertyutils. getproperty (bean, "double ")); Assertequals (jsonobject. Get ("func"), propertyutils. getproperty (bean, "func ")); Output: The JUnit test shows green bars, that is, the values are equal. Example 2 (convert to a specific bean ): String JSON = "{bool: True, integer: 1, string: \" JSON \"}"; Jsonobject = jsonobject. fromobject (JSON ); Beana bean = (beana) jsonobject. tobean (jsonobject, beana. Class ); Assertequals (jsonobject. Get ("bool"), Boolean. valueof (bean. isbool ())); Assertequals (jsonobject. Get ("integer"), new INTEGER (bean. getinteger ())); Assertequals (jsonobject. Get ("string"), Bean. getstring ()); Note: beana is the getters & setters Method for specific attributes. 5. Java-JSON mutual conversion filter-filter attributes when converting Java type to JSON. Here we will demonstrate instance 1 in 3: Instance 1: Map map = new hashmap (); Map. Put ("name", "JSON "); Map. Put ("bool", Boolean. True ); Map. Put ("int", new INTEGER (1 )); Map. Put ("arr", new string [] {"A", "B "}); Map. Put ("func", "function (I) {return this. Arr [I];}"); Jsonconfig = new jsonconfig (); Jsonconfig. setjsonpropertyfilter (New propertyfilter (){ Public Boolean apply (Object source, string name, object Value ){ If (value! = NULL & number. Class. isassignablefrom (value. getclass ())){ Return true; } Return false; } }); Jsonobject JSON = jsonobject. fromobject (MAP, jsonconfig ); System. Out. println (JSON ); Output: {"func": function (I) {return this. arr [I] ;}, "arr": ["A", "B"], "bool": True, "name": "JSON "} And the above output: {"func": function (I) {return this. arr [I] ;}, "arr": ["A", "B"], "int": 1, "bool": True, "name ": "JSON "} It is missing: "int": 1, this section, this is the role of the attribute filter, you can see the code to know it to filter out the value of the number type. Instance 2: What if we change number. Class. isassignablefrom (value. getclass () in the above example to string? Map map = new hashmap (); Map. Put ("name", "JSON "); Map. Put ("bool", Boolean. True ); Map. Put ("int", new INTEGER (1 )); Map. Put ("arr", new string [] {"A", "B "}); Map. Put ("func", "function (I) {return this. Arr [I];}"); Jsonconfig = new jsonconfig (); Jsonconfig. setjsonpropertyfilter (New propertyfilter (){ Public Boolean apply (Object source, string name, object Value ){ If (value! = NULL & string. Class. isassignablefrom (value. getclass () {// The Key To Filtering Return true; } Return false; } }); Jsonobject JSON = jsonobject. fromobject (MAP, jsonconfig ); System. Out. println (JSON ); Output: {"arr": ["A", "B"], "int": 1, "bool ": true} // It filters out all values of the string type. 6. JSON-Java mutual conversion filter-same as 5 this time -- filter attributes when converting JSON-to Java. Here we will demonstrate instance 1 in 4: Instance 1: String JSON = "{name = \" JSON \ ", bool: True, INT: 1, double: 2.2, FUNC: function (a) {return a ;}, array: [1, 2]} "; Jsonobject = jsonobject. fromobject (JSON ); Jsonconfig = new jsonconfig (); Jsonconfig. setrootclass (Map. Class ); Jsonconfig. setjavapropertyfilter (New propertyfilter (){ Public Boolean apply (Object source, string name, object Value ){ If ("bool". Equals (name) | "double". Equals (name) {// The Key To Filtering Return true; } Return false; } }); Object bean = jsonobject. tobean (jsonobject, jsonconfig ); System. Out. println (bean ); Output: {func = function (a) {return a ;}, Int = 1, name = JSON, array = [1, 2]} Same as instance 1 Output in 4: {double = 2.2, func = function (a) {return a ;}, Int = 1, name = JSON, bool = true, array = [1, 2]} Missing: Double = 2.2, bool = true, because the items with name bool and double have been filtered out. Instance 2: String JSON = "{name = \" JSON \ ", bool: True, INT: 1, double: 2.2, FUNC: function (a) {return a ;}, array: [1, 2]} "; Jsonobject = jsonobject. fromobject (JSON ); Jsonconfig = new jsonconfig (); Jsonconfig. setrootclass (Map. Class ); Jsonconfig. setjavapropertyfilter (New propertyfilter (){ Public Boolean apply (Object source, string name, object Value ){ If (value! = NULL & string. Class. isassignablefrom (value. getclass () {// The Key To Filtering Return true; } Return false; } }); Object bean = jsonobject. tobean (jsonobject, jsonconfig ); System. Out. println (bean ); Output: {double = 2.2, func = function (a) {return a ;}, Int = 1, bool = true, array = [1, 2]} It can be seen that, whether Java is converted to JSON or JSON to Java, the filter can be filtered by name and value.