Java中的 FieldPosition toString() 方法与示例

Java.text.FieldPosition类的toString()方法用于以字符串的形式表示字段位置对象。

句法：

public String toString()

参数：此方法不接受任何参数作为参数。

返回值：此方法返回此 FieldPosition 对象的字符串表示形式。

下面是说明toString()方法的示例：

示例 1：

// Java program to demonstrate
// toString() method
  
import java.text.*;
import java.util.*;
import java.io.*;
  
public class GFG {
    public static void main(String[] argv)
    {
        try {
  
            // Creating and initializing
            // new FieldPosition Object
            FieldPosition pos
                = new FieldPosition(
                    MessageFormat.Field.ARGUMENT);
  
            // getting the String representation
            // of this FieldPosition Object
            // using toString() method
            String str = pos.toString();
  
            // display result
            System.out.println("FieldPosition :- " + str);
        }
  
        catch (ClassCastException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

FieldPosition :- java.text.FieldPosition[field=-1, attribute=java.text.MessageFormat$Field(message argument field), beginIndex=0, endIndex=0]

示例 2：

// Java program to demonstrate
// toString() method
  
import java.text.*;
import java.util.*;
import java.io.*;
  
public class GFG {
    public static void main(String[] argv)
    {
        try {
  
            // Creating and initializing
            // new FieldPosition Object
            FieldPosition pos
                = new FieldPosition(
                    DateFormat.Field.AM_PM);
  
            // getting the String representation
            // of this FieldPosition Object
            // using toString() method
            String str = pos.toString();
  
            // display result
            System.out.println("FieldPosition :- " + str);
        }
  
        catch (ClassCastException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

FieldPosition :- java.text.FieldPosition[field=-1, attribute=java.text.DateFormat$Field(am pm), beginIndex=0, endIndex=0]

参考： https://docs.oracle.com/javase/9/docs/api/ Java/text/FieldPosition.html#toString–