Java中的 FieldPosition getField() 方法与示例

Java.text.FieldPosition类的getField()方法用于检索该字段位置对象的字段标识符。
句法：

public int getField()

参数：此方法不接受任何参数作为参数。
返回值：该方法返回该字段位置对象的字段标识符。
以下是说明getField()方法的示例：
示例 1：

Java

// Java program to demonstrate
// getField() 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 Field attribute
            // of FieldPosition object
            // using getField() method
            int i = pos.getField();
 
            // display result
            System.out.println(
                "field attribute :- "
                + Integer.toString(i));
        }
 
        catch (ClassCastException e) {
 
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

field attribute :- -1

示例 2：

Java

// Java program to demonstrate
// getField() 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 Field attribute
            // of FieldPosition object
            // using getField() method
            int i = pos.getField();
 
            // display result
            System.out.println(
                "field attribute :- "
                + Integer.toString(i));
        }
 
        catch (ClassCastException e) {
 
            System.out.println("Exception thrown : " + e);
        }
    }
}

输出：

field attribute :- -1

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