📅 最后修改于: 2020-09-27 02:16:20 🧑 作者: Mango
Java SequenceInputStream类用于从多个流中读取数据。它顺序读取数据(一一读取)。
让我们看一下Java.io.SequenceInputStream类的声明：
public class SequenceInputStream extends InputStream
| Constructor | Description |
|---|---|
| SequenceInputStream(InputStream s1, InputStream s2) | creates a new input stream by reading the data of two input stream in order, first s1 and then s2. |
| SequenceInputStream(Enumeration e) | creates a new input stream by reading the data of an enumeration whose type is InputStream. |
| Method | Description |
|---|---|
| int read() | It is used to read the next byte of data from the input stream. |
| int read(byte[] ary, int off, int len) | It is used to read len bytes of data from the input stream into the array of bytes. |
| int available() | It is used to return the maximum number of byte that can be read from an input stream. |
| void close() | It is used to close the input stream. |
在此示例中，我们将打印两个文件testin.txt和testout.txt的数据。
package com.javatpoint;
import java.io.*;
class InputStreamExample {
public static void main(String args[])throws Exception{
FileInputStream input1=new FileInputStream("D:\\testin.txt");
FileInputStream input2=new FileInputStream("D:\\testout.txt");
SequenceInputStream inst=new SequenceInputStream(input1, input2);
int j;
while((j=inst.read())!=-1){
System.out.print((char)j);
}
inst.close();
input1.close();
input2.close();
}
}
在这里，我们假设您有两个文件：testin.txt和testout.txt，它们具有以下信息：
testin.txt：
Welcome to Java IO Programming.
testout.txt：
It is the example of Java SequenceInputStream class.
执行该程序后，您将获得以下输出：
输出：
Welcome to Java IO Programming. It is the example of Java SequenceInputStream class.
在此示例中，我们将两个文件testin1.txt和testin2.txt的数据写入另一个名为testout.txt的文件中。
package com.javatpoint;
import java.io.*;
class Input1{
public static void main(String args[])throws Exception{
FileInputStream fin1=new FileInputStream("D:\\testin1.txt");
FileInputStream fin2=new FileInputStream("D:\\testin2.txt");
FileOutputStream fout=new FileOutputStream("D:\\testout.txt");
SequenceInputStream sis=new SequenceInputStream(fin1,fin2);
int i;
while((i=sis.read())!=-1)
{
fout.write(i);
}
sis.close();
fout.close();
fin1.close();
fin2.close();
System.out.println("Success..");
}
}
输出：
Succeess...
testout.txt：
Welcome to Java IO Programming. It is the example of Java SequenceInputStream class.
如果需要从两个以上的文件中读取数据，则需要使用Enumeration。枚举对象可以通过调用Vector类的elements()方法获得。让我们看一个简单的示例，其中我们从4个文件中读取数据：a.txt，b.txt，c.txt和d.txt。
package com.javatpoint;
import java.io.*;
import java.util.*;
class Input2{
public static void main(String args[])throws IOException{
//creating the FileInputStream objects for all the files
FileInputStream fin=new FileInputStream("D:\\a.txt");
FileInputStream fin2=new FileInputStream("D:\\b.txt");
FileInputStream fin3=new FileInputStream("D:\\c.txt");
FileInputStream fin4=new FileInputStream("D:\\d.txt");
//creating Vector object to all the stream
Vector v=new Vector();
v.add(fin);
v.add(fin2);
v.add(fin3);
v.add(fin4);
//creating enumeration object by calling the elements method
Enumeration e=v.elements();
//passing the enumeration object in the constructor
SequenceInputStream bin=new SequenceInputStream(e);
int i=0;
while((i=bin.read())!=-1){
System.out.print((char)i);
}
bin.close();
fin.close();
fin2.close();
}
}
a.txt，b.txt，c.txt和d.txt具有以下信息：
a.txt：
Welcome
b.txt：
to
c.txt：
java
d.txt：
programming
输出：
Welcometojavaprogramming