Java 读取文件

由于项目的需要，需要写一个解析文件的类。 import java.io.EOFException;import java.io.IOException;import java.io.RandomAccessFile;import java.net.URL;import java.util.Hashtable;import com.nokia.mms.*;/** * * @author JavaAlpha 解析用户发送的自定义文件，生成原始内容文件 */public class SeedAudit{ MMMessage mms = new MMMessage(); MMDecoder decoder = new MMDecoder(); MMContent content = new MMContent(); public SeedAudit(String file) { // 将MMS文件写到byte数组中 byte[] mmsFile = readFile(file); // 将数组set到content中 content.setContent(mmsFile, 0, mmsFile.length); decoder.setMessage(mmsFile); try { decoder.decodeMessage(); mms = decoder.getMessage(); storeContents(mms); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (MMDecoderException e) { // TODO Auto-generated catch block e.printStackTrace(); } /*// 获取MMS文件的id String id = content.getContentId(); // 获取MMS文件的type String type = content.getType(); // 获取MMS文件长度 int length = content.getLength(); System.out.println("id--" + id); System.out.println("type--" + type); for (int i = 0; i < length; i++) { try { if (type.compareTo(IMMConstants.CT_TEXT_PLAIN) == 0) { // 如果文件类型是文本文件 content.saveToFile(id + ".txt"); } else if (type.compareTo(IMMConstants.CT_IMAGE_JPEG) == 0) { // 如果文件类型是jpg文件 content.saveToFile(id + ".jpg"); } else if (type.compareTo(IMMConstants.CT_IMAGE_GIF) == 0) { // 如果文件类型是gif文件 content.saveToFile(id + ".gif"); } else { content.saveToFile(id); } } catch (IOException e) { e.printStackTrace(); } }*/ } private void storeContents(MMMessage mm) throws IOException { MMContent mmContent = null; String path = getPath(); for (int j = 0; j < mm.getNumContents(); j++) { mmContent = mm.getContent(j); /*System.out.println(" Content " + j + " --> ID = " + mmContent.getContentId() + ", TYPE = " + mmContent.getType() + ", LENGTH = " + mmContent.getLength());*/ if ((mmContent.getType()).compareTo(IMMConstants.CT_IMAGE_WBMP) == 0) mmContent.saveToFile(path + cleanString(mmContent.getContentId()) + ".wbmp"); else if ((mmContent.getType()) .compareTo(IMMConstants.CT_TEXT_PLAIN) == 0) mmContent.saveToFile(path + cleanString(mmContent.getContentId()) + ".txt"); else if ((mmContent.getType()) .compareTo(IMMConstants.CT_APPLICATION_SMIL) == 0) mmContent.saveToFile(path + cleanString(mmContent.getContentId()) + ".smil"); else if ((mmContent.getType()) .compareTo(IMMConstants.CT_IMAGE_JPEG) == 0) mmContent.saveToFile(path + cleanString(mmContent.getContentId()) + ".jpg"); else if ((mmContent.getType()).compareTo(IMMConstants.CT_IMAGE_GIF) == 0) mmContent.saveToFile(path + cleanString(mmContent.getContentId()) + ".gif"); else if ((mmContent.getType()).compareTo("audio/wav") == 0) mmContent.saveToFile(path + cleanString(mmContent.getContentId()) + ".wav"); else mmContent.saveToFile(path + cleanString(mmContent.getContentId())); } } private String cleanString(String str) { String result; if ((str.charAt(0) == '<') && (str.charAt(str.length() - 1) == '>')) result = str.substring(1, str.length() - 1); else result = str; return result; } private String getPath() { URL url = getClass().getResource(getClass().getName() + ".class"); String classPath = url.getHost() + url.getFile(); int pos = classPath.lastIndexOf("/"); return classPath.substring(0, pos + 1); } // 读取文件 private byte[] readFile(String filename) { int fileSize = 0; RandomAccessFile fileH = null; // Opens the file for reading. try { fileH = new RandomAccessFile(filename, "r"); fileSize = (int) fileH.length(); } catch (IOException ioErr) { System.err.println("Cannot find " + filename); System.err.println(ioErr); System.exit(200); } // allocates the buffer large enough to hold entire file byte[] buf = new byte[fileSize]; // reads all bytes of file int i = 0; try { while (true) { try { buf[i++] = fileH.readByte(); } catch (EOFException e) { break; } } } catch (IOException ioErr) { System.out.println("ERROR in reading of file" + filename); } return buf; } public static void main(String[] args) { SeedAudit seed = new SeedAudit("e:/Sample.mms"); }}