文本输入与输出

1. PrintWriter()使用示例

package StreamAndFile;



import java.io.BufferedReader;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.PrintWriter;

import java.io.UnsupportedEncodingException;

import java.util.Calendar;

import java.util.GregorianCalendar;



public class TextFileTest {

    public static class Employee{

        String name;

        double salary;

        int year,month,day;

        public Employee(String name,double salary,int year,int month,int day){

            this.name=name;

            this.salary=salary;

            this.year=year;

            this.month=month;

            this.day=day;

        }

        public String getName() {

            return name;

        }

        

        public double getSalary() {

            return salary;

        }

        

        public int getYear() {

            return year;

        }



        public int getMonth() {

            return month;

        }



        public int getDay() {

            return day;

        }



    }

    //将数据写出到文件

    public static void writeData(Employee[] staff, PrintWriter out){

        for(int i=0;i<staff.length;i++){

            out.println(staff[i].getName()+"|"+staff[i].getSalary()+"|"+staff[i].getYear()+

                    "|"+staff[i].getMonth()+"|"+staff[i].getDay());

        }

        out.flush();

    }

    public static void main(String[] args) {

        Employee[] staff = new Employee[3];

        staff[0]=new Employee("Carl Cracker", 75000, 1987, 12, 15);

        staff[1]=new Employee("Harry Hacker", 50000, 1989, 10, 1);

        staff[2]=new Employee("Tony Tester", 40000, 1990, 3, 15);

        //将数据输出到文件employee.txt中

        try {

            PrintWriter out = new PrintWriter("D:\\employee.txt","UTF-8");

            writeData(staff,out);

            System.out.println("写出成功！");

            out.close();

        } catch (FileNotFoundException | UnsupportedEncodingException e) {

            e.printStackTrace();

        }

        //读入输出的文件中的数据

        FileInputStream fis;

        String str;

        try {

            fis = new FileInputStream("D:\\employee.txt");

            BufferedReader br = new BufferedReader(new InputStreamReader(fis));

            System.out.println("读出的数据为：");

            while((str=br.readLine())!=null){

                System.out.println(str);

            }

            br.close();

        } catch (FileNotFoundException e) {

            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();

        }

    }



}

程序运行结果如下：

写出成功！

读出的数据为：

Carl Cracker|75000.0|1987|12|15

Harry Hacker|50000.0|1989|10|1

Tony Tester|40000.0|1990|3|15

 2. 获得字符集别名及所有可用字符集

获得字符集别名：

package StreamAndFile;



import java.nio.charset.Charset;

import java.util.Set;

//输出字符集的别名

public class GetCharSet {



    public static void main(String[] args) {

        Charset cset = Charset.forName("ISO-8859-1");

        Set<String> aliases = cset.aliases();

        for(String aliase : aliases){

            System.out.println(aliase);

        }

    }



}

程序运行结果如下：

csISOLatin1

latin1

IBM-819

iso-ir-100

8859_1

ISO_8859-1:1987

ISO_8859-1

819

l1

ISO8859-1

IBM819

ISO_8859_1

ISO8859_1

cp819

 获得所有可用字符集：

package StreamAndFile;



import java.nio.charset.Charset;

import java.util.Map;

//输出字符集的别名

public class GetCharSet {



    public static void main(String[] args) {//输出所有可用的字符集的名字

        Map<String,Charset> charsets = Charset.availableCharsets();

        for(String name:charsets.keySet()){

            System.out.println(name);

        }

    }



}