String class

1、String.format()

logger.info(String.format("Print log %s,%s,%b", stringA,stringB,booleanC));

-- Detailed explanation of Java string formatting
https://www.cnblogs.com/travellife/p/Java-zi-fu-chuan-ge-shi-hua-xiang-jie.html

2. String StringBuilder StringBuffer
-- String, The difference between StringBuffer and StringBuilderhttp
://blog.csdn.net/helongzhong/article/details/54090754 --Thread
Safety-From the difference between StringBuffer and StringBuilderhttps:
//blog.csdn.net/djjt10/ article/details/52860010 --The
difference between String, StringBuffer and StringBuilder|Thread safety and thread insecurity
https://www.cnblogs.com/xingzc/p/6277581.html

3. toString() method
Method 1,

@Override
public String toString() {
	return "DemoClass[name=" + name+ ", age=" + age+ "]";
}

Method Two,

import org.apache.commons.lang.builder.ReflectionToStringBuilder;
@Override
public String toString() {
	return ReflectionToStringBuilder.toString(this);
}

Method three, with the help of JSON tool class

import com.alibaba.fastjson.JSONObject;
	@Override
    public String toString() {
        return JSONObject.toJSONString(this);
    }