Java-IO

 1 public class member {
 2     private string name;  
 3     private int age;  
 4     public member() {  
 5     }  
 6    public member(string name, int age) {  
 7         this.name = name;  
 8         this.age = age;  
 9     }  
10     public void setname(string name){  
11         this.name = name;  
12     }  
13     public void setage(int age) {  
14         this.age = age;  
15     }  
16     public string getname() {  
17         return name;  
18     }  
19     public int getage() {  
20         return age;  
21     }  
22 }

 1 import java.io.datainputstream;
 2 import java.io.dataoutputstream;
 3 import java.io.fileinputstream;
 4 import java.io.fileoutputstream;
 5 import java.io.ioexception;
 6 
 7 /**
 8  * dataoutputstream
 9  */
10 public class datastreamtest {
11     public static void main(string[] args) {
12         member[] members = { new member("justin", 90), 
13                              new member("momor", 95), 
14                              new member("bush", 88) };
15         try {
16             dataoutputstream dos = new dataoutputstream(new fileoutputstream("e:/member.txt"));
17             for (member member : members) {
18                 // 写入utf字符串
19                 dos.writeutf(member.getname());
20                 // 写入int数据
21                 dos.writeint(member.getage());
22             }
23             dos.flush();// 将流中的数据刷新到目的地
24             dos.close();// 关闭流
25 
26             datainputstream dis = new datainputstream(new fileinputstream("e:/member.txt"));
27             // 读出数据并还原为对象
28             for (int i = 0; i < members.length; i++) {
29                 string name = dis.readutf();// 读出utf字符串
30                 int score = dis.readint();// 读出int数据
31                 members[i] = new member(name, score);
32             }
33             dis.close();// 关闭流
34 
35             // 显示还原后的数据
36             for (member member : members) {
37                 system.out.printf("%s\t%d%n", member.getname(), member.getage());
38             }
39         } catch (ioexception e) {
40             e.printstacktrace();
41         }
42     }
43 }

 1 import java.io.file;
 2 import java.io.fileinputstream;
 3 import java.io.ioexception;
 4 import java.io.inputstream;
 5 
 6 /**
 7  * fileinputstream  字节输入流
 8  */
 9 public class fileinputstreamtest {
10     public static void main(string[] args) {
11         inputstream in = null;//文件输入流  
12          try{  
13              in = new fileinputstream(new file("e:/fileinputstreamtest.txt"));  
14              /*
15               * fileinputstream是有缓冲区的，所以用完之后必须关闭，否则可能导致内存占满，数据丢失。 
16               */  
17              int i = 0;//接收读取的内容
18              //streamreader.read()从文件读取一个字节，并当做int类型返回，如果遇到文件末尾，则返回-1
19              while((i = in.read())!=-1) {
20                  system.out.print((char)i);//打印读取的内容
21              }  
22          }catch (final ioexception e) {  
23              e.printstacktrace();  
24          }finally{  
25              try{  
26                  in.close();  //关闭流
27              }catch (ioexception e) {  
28                 e.printstacktrace();  
29              }  
30          }  
31     }
32 }

 1 import java.io.fileinputstream;
 2 import java.io.fileoutputstream;
 3 import java.io.ioexception;
 4 
 5 /**
 6  * 文件拷贝
 7  */
 8 public class filecopy {
 9     public static void main(string[] args) {
10          byte[] b=new byte[512];   //一次取出的字节数大小,缓冲区大小  
11          int i=0;  
12          fileinputstream input=null;  
13          fileoutputstream out =null;  
14          try {  
15             input=new fileinputstream("e:/fileinputstreamtest.txt");  
16             out=new fileoutputstream("e:/copy.txt",true); //如果文件不存在会自动创建,true表示写在文件末尾  
17              
18             while ((i=input.read(b))!=-1) { //i的目的在于防止最后一次读取的字节小于b长度,否则会自动被填充0
19                 //使用输出流写入读取的内容到指定文件
20                out.write(b, 0, i);
21             }  
22          } catch (final ioexception e) {  
23             e.printstacktrace();  
24          }finally{  
25             try {  
26                input.close();  
27                out.close();  
28             } catch (ioexception e) {  
29                e.printstacktrace();  
30             }  
31          }  
32     }
33 }

 1 import java.io.bufferedreader;
 2 import java.io.bufferedwriter;
 3 import java.io.file;
 4 import java.io.filereader;
 5 import java.io.filewriter;
 6 import java.io.ioexception;
 7 
 8 /**
 9  * bufferedreader、bufferedwriter
10  */
11 public class filewritertest {
12     public static void main(string[] args) throws ioexception{
13         bufferedreader br = new bufferedreader(new filereader(new file("e:/printtest.txt")));
14         bufferedwriter bw = new bufferedwriter(new filewriter(new file("e:/writecopy.txt")));
15         
16         string str = null;
17         try {
18             while((str = br.readline())!=null) { //一次读一行
19                 bw.write(str);
20             }
21         } catch (ioexception e) {
22             e.printstacktrace();
23         }finally {
24             br.close();
25             bw.close();
26         }
27     }
28 }

 1 import java.io.serializable;
 2 
 3 public class student implements serializable{
 4     
 5     private static final long serialversionuid = 1l;
 6     private string name;  
 7     private int age;  
 8     public student() {}
 9     public string getname() {
10         return name;
11     }
12     public void setname(string name) {
13         this.name = name;
14     }
15     public int getage() {
16         return age;
17     }
18     public void setage(int age) {
19         this.age = age;
20     }
21     public student(string name, int age) {  
22          this.name = name;  
23          this.age = age;  
24     }  
25     @override  
26     public string tostring() {  
27         return "student [name=" + name + ", age=" + age + "]";  
28     }  
29 }

 1 import java.io.fileinputstream;
 2 import java.io.fileoutputstream;
 3 import java.io.ioexception;
 4 import java.io.objectinputstream;
 5 import java.io.objectoutputstream;
 6 import java.util.arraylist;
 7 import java.util.list;
 8 
 9 /**
10  *    objectoutputstream
11  */
12 public class objectstream {
13     public static void main(string[] args) {
14         // 对象输入输出流
15         objectoutputstream ow = null;
16         objectinputstream or = null;
17         list<student> stulist = new arraylist<student>();
18         object obj = null;
19         try {
20             // 先将对象输出到文件中
21             ow = new objectoutputstream(new fileoutputstream("e:/student.txt"));
22             ow.writeobject(new student("gg", 22));
23             ow.writeobject(new student("tt", 18));
24             ow.writeobject(new student("rr", 17));
25             ow.writeobject(null);//添加一个null  是为了后续判断是否读取到末尾
26             // 然后从该文件读取对象
27             or = new objectinputstream(new fileinputstream("e:/student.txt"));
28             
29             while((obj = or.readobject())!=null) {
30                 stulist.add((student) obj);// 将读取的对象强转成student对象
31             }
32             for (student student : stulist) {
33                 system.out.println(student.getname() + "-" + student.getage());
34             }
35         } catch (ioexception e) {
36             e.printstacktrace();
37         } catch (classnotfoundexception e) {
38             e.printstacktrace();
39         } finally {
40             try {
41                 ow.close();
42                 or.close();//关闭流
43             } catch (ioexception e) {
44                 e.printstacktrace();
45             }
46         }
47     }
48 }

 1 import java.io.filereader;
 2 import java.io.ioexception;
 3 import java.io.printwriter;
 4 
 5 /**
 6  * printwriter
 7  */
 8 public class printtest {
 9     public static void main(string[] args) {
10         filereader reader=null;        //读取字符文件的流  
11         printwriter writer=null;    //写字符到控制台的流  
12         char[] b=new char[512];   //一次取出的字节数大小,缓冲区大小  
13         int i=0;  
14         try {  
15            reader=new filereader("e:/fileinputstreamtest.txt");  
16            //writer=new printwriter(system.out);  //输出到控制台
17            writer=new printwriter("e:/printtest.txt");  //输出指定文件，没有自动创建
18            
19            while ((i = reader.read(b))!=-1) {  
20               writer.write(b, 0, i);  
21            }  
22         } catch (ioexception e) {  
23            e.printstacktrace();  
24         }finally{  
25            try {  
26               reader.close();  
27            } catch (ioexception e) {  
28               e.printstacktrace();  
29            }  
30            writer.close();
31         }  
32     }
33 }

 1 import java.io.bytearrayinputstream;
 2 import java.io.ioexception;
 3 import java.io.pushbackinputstream;
 4 /**
 5  * 回退流：pushbackinputstream类继承了filterinputstream类是iputstream类的修饰者。
 6  * 提供可以将数据插入到输入流前端的能力(当然也可以做其他操作)。
 7  * 简而言之pushbackinputstream类的作用就是能够在读取缓冲区的时候提前知道下一个字节是什么，
 8  * 其实质是读取到下一个字符后回退的做法，这之间可以进行很多操作，这有点向你把读取缓冲区的过程当成一个数组的遍历，
 9  * 遍历到某个字符的时候可以进行的操作，
10  * 当然，如果要插入，能够插入的最大字节数是与推回缓冲区的大小相关的，插入字符肯定不能大于缓冲区吧！
11  */
12 public class pushbackinputstreamtest {
13     public static void main(string[] args) throws ioexception {
14         string str = "hello,rollenholt";  
15         pushbackinputstream push = null; // 声明回退流对象  
16         bytearrayinputstream bat = null; // 声明字节数组流对象  
17         bat = new bytearrayinputstream(str.getbytes());  
18         push = new pushbackinputstream(bat); // 创建回退流对象，将拆解的字节数组流传入  
19         int temp = 0;  
20         while ((temp = push.read()) != -1) { // push.read()逐字节读取存放在temp中，如果读取完成返回-1  
21            if (temp == ',') { // 判断读取的是否是逗号
22               push.unread(temp); //回到temp的位置  
23               temp = push.read(); //接着读取字节  
24               system.out.print("(回退" + (char) temp + ") "); // 输出回退的字符  
25            } else {  
26               system.out.print((char) temp); // 否则输出字符  
27            }  
28         }  
29     }
30 }

 1 import java.io.bufferedoutputstream;
 2 import java.io.fileinputstream;
 3 import java.io.filenotfoundexception;
 4 import java.io.fileoutputstream;
 5 import java.io.ioexception;
 6 import java.io.inputstream;
 7 import java.io.sequenceinputstream;
 8 import java.util.enumeration;
 9 import java.util.vector;
10 
11 /**
12  * sequenceinputstream
13  */
14 public class sequenceinputstreamtest {
15      /** 
16        *  sequenceinputstream合并流，
17        *   将与之相连接的流集组合成一个输入流并从第一个输入流开始读取， 
18        *   直到到达文件末尾，接着从第二个输入流读取，依次类推，直到到达包含的最后一个输入流的文件末尾为止。 
19        *   合并流的作用是将多个源合并合一个源。可接收枚举类所封闭的多个字节流对象。 
20        */  
21       public static void main(string[] args) {  
22          dosequence();  
23       }  
24       private static void dosequence() {  
25          // 创建一个合并流的对象  
26          sequenceinputstream sis = null;  
27          // 创建输出流。  
28          bufferedoutputstream bos = null;  
29          try {  
30             // 构建流集合。  
31             vector<inputstream> vector = new vector<inputstream>();  
32             vector.addelement(new fileinputstream("e:/text1.txt"));  
33             vector.addelement(new fileinputstream("e:/text2.txt"));  
34             vector.addelement(new fileinputstream("e:/text3.txt"));  
35             enumeration<inputstream> e = vector.elements();  
36        
37             sis = new sequenceinputstream(e);  //将多个输入流合并到合并流
38             bos = new bufferedoutputstream(new fileoutputstream("e:/text4.txt",true));//true追加末尾
39             // 读写数据  
40             byte[] buf = new byte[1024];  
41             int len = 0;  
42             while ((len = sis.read(buf)) != -1) {  
43                bos.write(buf, 0, len);  
44                bos.flush();
45             }  
46          } catch (filenotfoundexception e1) {  
47             e1.printstacktrace();  
48          } catch (ioexception e1) {  
49             e1.printstacktrace();  
50          } finally {  
51             try {  
52                if (sis != null)  
53                   sis.close();  
54             } catch (ioexception e) {  
55                e.printstacktrace();  
56             }  
57             try {  
58                if (bos != null)  
59                   bos.close();  
60             } catch (ioexception e) {  
61                e.printstacktrace();  
62             }  
63          }  
64       }  
65 }