Commons Lang、ToStringBuilder#append

import org.apache.commons.lang.builder.ToStringBuilder;

public class C2009062300 {
    boolean   boolean_value;
    boolean[] boolean_values = { true, false };
    char      char_value = 'a';
    char[]    char_values = { 'a', 'b', 'c' };
    double    double_value = 1.2;
    double[]  double_values = { 1.2 };

    public String toString() {
        return new ToStringBuilder(this).
            append("boolean",   boolean_value).
            append("boolean[]", boolean_values).
            append("char",      char_value).
            append("char[]",    char_values).
            append("double",    double_value).
            append("double[]",  double_values).
            toString();
    }

    public static void main(String[] args) {
        System.out.println(new C2009062300());
    }
}

で、

C2009062300@c17164[boolean=false,boolean[]={true,false},char=a,char[]={a,b,c},double=1.2,double[]={1.2}]