ToStringBuilder

     ToStringBuilder类主要用于类的格式化输出。ToStringBuilder中append方法可以向该类添加基本类型、数组、和对象，只有添加的方法才会被toString输出。如：

class TaxReturn {
  private String ssn;
  private int year;
  private String lastName;
  private BigDecimal taxableIncome;
  // get/set方法省略
  public TaxReturn() {
  }
public TaxReturn(String pSsn, int pYear, String pLastName, BigDecimal pTaxableIncome) {
    setSsn(pSsn);
    setYear(pYear);
    setLastName(pLastName);
    setTaxableIncome(pTaxableIncome);
  }
  public String toString() {
    return new ToStringBuilder(this).append("ssn", ssn).append("year", year).append("lastName",
        lastName).toString();
  }
 
  public int hashCode() {
    return new HashCodeBuilder(3, 7).append(ssn).append(year).toHashCode();
  }
 
  public boolean equals(Object pObject) {
    boolean equals = false;
    if (pObject instanceof TaxReturn) {
      TaxReturn bean = (TaxReturn) pObject;
      equals = (new EqualsBuilder().append(ssn, bean.ssn).append(year, bean.year)).isEquals();
    }
    return equals;
  }
 
  public int compareTo(Object pObject) {
    return CompareToBuilder.reflectionCompare(this, pObject);
  }
 
}
 
public class MainClass {
 
  public static void main(String[] pArgs) throws Exception {
     TaxReturn return1 = new TaxReturn("012-68-3242", 1998, "O'Brien", new BigDecimal(43000.00));
     TaxReturn return2 = new TaxReturn("012-68-3242", 1999, "O'Brien", new BigDecimal(45000.00));
     TaxReturn return3 = new TaxReturn("012-68-3242", 1999, "O'Brien", new BigDecimal(53222.00));
     System.out.println("ToStringBuilder: " + return1.toString());
  }
}
运行结果如下：
   ToStringBuilder: TaxReturn@1503a3[ssn=012-68-3242,year=1998,lastName=O'Brien]
 
 
2、ToStringBuilder的reflectionToString方法
 
     该方法主要是把类对应的基本属性和值输出来。如：
public class MainClass {
    public static void main(String[] args) {
        MyClass one = new MyClass("Becker", 35);
        MyClass two = new MyClass("Becker", 35);
        MyClass three = new MyClass("Agassi", 33);
 
        System.out.println("One>>>" + one);
        System.out.println("Two>>>" + two);
        System.out.println("Three>>>" + three);
 
        System.out.println("one equals two? " + one.equals(two));
        System.out.println("one equals three? " + one.equals(three));
 
        System.out.println("One HashCode>>> " + one.hashCode());
        System.out.println("Two HashCode>>> " + two.hashCode());
        System.out.println("Three HashCode>>> " + three.hashCode());
    }
}
 
class MyClass {
    private String name = null;
    private int age = 0;
 
    public MyClass(String name, int age) {
        this.name = name;
        this.age = age;
    }
 
    public boolean equals(Object obj) {
        return EqualsBuilder.reflectionEquals(this, obj);
    }
 
    public String toString() {
        return ToStringBuilder.reflectionToString(this,
            ToStringStyle.MULTI_LINE_STYLE);
    }
 
    public int hashCode() {
        return HashCodeBuilder.reflectionHashCode(this);
    }
}