Blog: mkyong (Yong Mook Kim) |
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286 blogs
updated: 39 min. ago
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Gson provide simple toJson() and fromJson() methods to convert Java objects to / from JSON. toJson() Java object to JSON Gson gson = new Gso...
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Few Jackson examples to convert a JSON array string to a List // JSON array string // [{"name":"mkyong", "age":37}, {"name":"fong", "age":38...
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In Jackson, we can use @JsonInclude(JsonInclude. Include.NON_NULL) to ignore the null fields. P.S Tested with Jackson 2.9.8 1. Jackson defau...
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Start a Java class and hits this java.lang.UnsupportedClas sVersionError, what is class file version 52 56? Error: A JNI error has occurred,...
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In Java, we can use javap -verbose className to print out the class information. Terminal D:\projects>javap -verbose Test Classfile /D:/proj...
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In the old days, we can use list.toArray(new String[0]) to convert a ArrayList into a String[] StringArrayExample.java package com.mkyong; i...
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In Java, we can use java.util.Scanner to get user input from console. 1. Scanner 1.1 Read a line. UserInputExample1.java package com.mkyong;...
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In Java, for primitive types, parameters are pass-by-value; For object types, object reference is pass-by-value, however, Java is allowed to...
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A simple List.add() and hits the following java.lang.UnsupportedOper ationException ListExample.java package com.mkyong; import java.util.Ar...
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A Java 2d array example. ArrayExample.java package com.mkyong; public class ArrayExample { public static void main(String[] args) { int[][] ...
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