笔记 —— SequenceInputStream

Dear 丶 2022-03-22 08:37 120阅读 0赞

序列流：`SequenceInputStream`

> 序列流应用场景：将多个文件整合到一个文件中

#### 一、整合2个文件 ####

try { 
                FileInputStream fis3 = new FileInputStream("a.txt");
                FileInputStream fis4 = new FileInputStream("b.txt");
                SequenceInputStream sis = new SequenceInputStream(fis3, fis4);
                FileOutputStream fos = new FileOutputStream("c.txt");
                
                int b;
                while ((b = sis.read()) != -1) { 
                    fos.write(b);
                }
                
                sis.close();  // SequenceInputStream 的 close() 方法 会遍历关闭字节流对象
                fos.close();
            } catch (IOException e) { 
                e.printStackTrace();
            }

#### 二、整合多个文件 ####

try { 
                FileInputStream fis1 = new FileInputStream("a.txt");
                FileInputStream fis2 = new FileInputStream("b.txt");
                FileInputStream fis3 = new FileInputStream("c.txt");
    
                Vector<FileInputStream> vector = new Vector<>();
                vector.add(fis1);
                vector.add(fis2);
                vector.add(fis3);
    
                Enumeration<FileInputStream> enumeration = vector.elements();
                SequenceInputStream sis = new SequenceInputStream(enumeration);
                FileOutputStream fos = new FileOutputStream("d.txt");
    
                int b;
                while ((b = sis.read()) != -1) { 
                    fos.write(b);
                }
    
                sis.close();  
                fos.close();
            } catch (IOException e) { 
                e.printStackTrace();
            }