文件缓存类

文件缓存最好用请求地址作为文件名的唯一标识

public class CacheUtils {

	public  CacheUtils cacheUtil;
	public Context context;
	public HttpInstance httpInstance = new HttpInstance();
	private FileReader fileReader;

	public CacheUtils(Context context) {
		super();
		this.context = context;
		//context = AppApplication.geContext();
		//getCacheUtilInstance();
	}

	/*public static CacheUtils getCacheUtilInstance() {
		// TODO Auto-generated method stub
		if (cacheUtil == null) {
			cacheUtil = new CacheUtils();
			return cacheUtil;
		}
		return cacheUtil;
	}*/

	public String cacheData(String coursesWekeUrl, OnHttpRequest onHttpRequest, boolean isHttpRequest) {
		String path = context.getExternalCacheDir().getPath();
		String encode = null;
		String data = null;
		try {
			encode = URLEncoder.encode(coursesWekeUrl, "utf-8");
		} catch (UnsupportedEncodingException e1) {
			e1.printStackTrace();
		}
		File file = new File(path, encode);
		if (isHttpRequest) {
			try {
				data = httpInstance.getInstance().doHttpGet(coursesWekeUrl);
				Log.e("isHttpRequestisHttpRequest",data);
			} catch (Exception e) {
				e.printStackTrace();
				if (onHttpRequest != null) {
					onHttpRequest.OnHttpRequestFailed(e);
				}
			}
			httpRequestResultWrite(data, file);
			return data;
		}
		char[] chars = new char[1024*10];
		Log.e("readerreaderreader",file.exists()+"");
		Log.e("readerreaderreader",file.isFile()+"");
		Log.e("readerreaderreader",file.length()+"");
		StringBuilder builder =new StringBuilder();
		if (file.exists() && file.isFile() && file.length() > 0) {
			
			//data = readerCacheFile(file);
				try {
					fileReader = new FileReader(file);
					int  len=0;
					while((len = fileReader.read(chars))!=-1){
						builder.append(chars, 0, len);
					}
					if(builder.toString().length()>0){
						data=builder.toString();
						Log.e("readerreaderreader",data);
					}
				} catch (Exception e) {
					e.printStackTrace();
				}finally {
					closeStream( fileReader);
				}
				
		} else {
			try {
				data = httpInstance.getInstance().doHttpGet(coursesWekeUrl);
				Log.e("elseelse",data);
				httpRequestResultWrite(data, file);
			} catch (Exception e) {
				e.printStackTrace();
				if (onHttpRequest != null) {
					onHttpRequest.OnHttpRequestFailed(e);
				}
			}
			
		}

		return data;
	}

	/*
	 * 读取缓存文件方法
	 */
	private String readerCacheFile(File file) {
		FileReader fileReader = null;
		char[] chars = new char[1024 * 10];
		int len = 0;
		String data = null;
		StringBuilder builder = new StringBuilder();
		try {
			fileReader = new FileReader(file);
			while ((len = fileReader.read(chars)) != -1) {
				builder.append(chars, 0, len);
			}
			if (builder.toString().length() > 0) {
				data = builder.toString();
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			closeStream(fileReader);
		}
		return data;
	}

	/*
	 * 网路请求方法
	 */
	private void httpRequestResultWrite(String data, File file) {
		FileWriter fileWriter = null;
		try {
			file.createNewFile();
			fileWriter = new FileWriter(file);
			fileWriter.write(data);
			fileWriter.flush();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			closeStream(fileWriter);

		}
	}

	/*
	 * 关闭流对象方法
	 */
	public void closeStream(Closeable fileReader) {
		if (fileReader != null) {
			try {
				fileReader.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	/*
	 * 请求失败的接口
	 */
	public interface OnHttpRequest {
		void OnHttpRequestFailed(Exception e);
	}
}