第六章 JSP文件操作（续）.ppt

1、第六章 JSP文件操作(续),西南科技大学网络教育系列课程 动态网页设计（JSP）,字符流,在实际应用中，存在一类文本数据，它们可能采用各种不同的字符编码方式(字符集)，可能是单字节字符，也可能是多字节字符，这就需要借助于字符流来处理文本类信息。读取器(Reader)和写出器(Writer)是所有字符流的超类，它们是直接继承Object类的抽象类。,字符输入流的类层次结构,字符输入流,常用方法：,public abstract void close() throws IOException,public int read() throws IOException,public int read

2、(char cbuf) throws IOException,public abstract int read(char cbuf, int off, int len) throws IOException,public long skip(long n) throws IOException,字符输入流,FileReader类,public FileReader(String fileName) throws FileNotFoundException,public FileReader(File file) throws FileNotFoundException,实例：用字符输入流读取文

3、件 fileReaderExample1.jsp,字符流,字符输出流的类层次结构,字符输出流,Writer类常用方法,public void write(String str) throws IOException public void write(char cbuf) throws IOException public abstract void write(char cbuf, int off, int len)throws IOException,public abstract void close() throws IOException,public abstract void f

4、lush() throws IOException,字符输出流,FileWriter类,public FileWriter(String fileName) throws IOException public FileWriter(File file) throws IOException public FileWriter(String fileName, boolean append) throws IOException,public BufferedWriter(Writer out),public BufferedWriter(Writer out, int sz),FileWrit

5、er类,实例：用字符输出流写文件 filewriterExample1.jsp,6.4随机读写文件,RandomAccessFile和FileInputStream和FileOutputStream不同，它既可以读取一个文件，也可以写入一个文件。,RandomAccessFile类具有如下的构建器：,public RandomAccessFile(String name, String mode) throws FileNotFoundException,public RandomAccessFile(File file, String mode) throws FileNotFoundExc

6、eption,其中第一个参数使用文件名或File对象指定一个文件。第二个参数mode指定文件的打开方式，mode为“r”时，指定文件按只读方式打开；mode为“rw”时，文件按只读写方式打开。,RandomAccessFile的方法,public void close() throws IOException,public long getFilePointer() throws IOException,public long length() throws IOException,public int read() throws IOException,public final void r

7、eadFully(byte b) throws IOException,public final String readLine() throws IOException,RandomAccessFile的方法,public void seek(long pos) throws IOException,public void setLength(long newLength) throws IOException,public void write(byte b) throws IOException,public final void writeByte(int v) throws IOEx

8、ception,程序实例：随机读取文件程序示例 RandomAccessFileExample1.jsp,程序实例：故事接龙 InputStory.jsp,文件的上传与下载,用普通方法实现文件上传,实例：文件上传,UploadFileExample1.jsp,AccepteUploadFile.jsp,实例：文件下载DownFileExample2.jsp,用组件实现文件的上传与下载,jspSmartUpload,组件安装,相关类的介绍,File类,savaAs()方法,savaAs(String dstFileName),savaAs(String dstFileName,int savaA

9、sOption),SAVEAS_PHYSICAL,SAVEAS_VIRTUAL,jspSmartUpload相关类的介绍,File类,isMissing(),getFieldName(),getFileName(),Files类,getCount(),getSize(),getCollection(),jspSmartUpload相关类的介绍,request类,smartUpload类,Initialize(),upload(),save(),getRequest(),getFiles(),setAllowedFileList(String allowedFilesList),jspSmartUpload相关类的介绍,smartUpload类,setDeniedFilesList(),setMaxFileSize(),setTotalMaxFileSize(),downloadFile(),实例：用jspSmartUpload组件实现文件上传 uploadFile.html do_upload.jsp,实例：应用jspSmartUpload组件进行较复杂的表单处理 uploadFile2.html do_upload2.jsp,文件的分页显示,实例：分页读取文件内容 fenye.jsp,小结,