android 解决asset下面文件太大报错问题

public static void separate()  throws IOException{
		
		//需要分割的文件放置的路径
		String path = "E:/";
		//需要分割的文件的文件名称
		String base = "demo";
		//需要分割的文件的后缀名
		String ext = ".db";
		//以每个小文件1024*1024字节即1M的标准来分割
		int split = 1024 * 1024;
		byte[] buf = new byte[1024];
		int num = 1;
		//建立输入流
		File inFile = new File(path + base + ext);
		FileInputStream fis = new FileInputStream(inFile);
		while (true) {
		//以"demo"+num+".db"方式来命名小文件即分割后为demo1.db，demo2.db，。。。。。。
		FileOutputStream fos = new FileOutputStream(new File(path + base + num + ext));
		for (int i = 0; i < split / buf.length; i++) {
		int read = fis.read(buf);
		fos.write(buf, 0, read);
		// 判断大文件读取是否结束
		if (read < buf.length) {
		fis.close();
		fos.close();
		return;
		}
		}
		fos.close();
		num++;
		}
	}

package util;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.content.res.AssetManager;
import android.os.Environment;


public class DBUtil {
	
	private Context context;
	private String pathinfo = Environment.getExternalStorageDirectory().getAbsolutePath()+"demo.db";
	
	public DBUtil(Context context){
		this.context = context;
	}
	
	public void getAsset(){
		AssetManager assetManager = context.getAssets();
		try {
			String[] data = assetManager.list("");
			mergeFile(context, data, pathinfo);
		} catch (IOException e) {
			e.printStackTrace();
		} 
	}
		 
		public  void mergeFile(Context c, String[] partFileList, String dst) throws IOException {
			if (!new File(dst).exists()) {
				OutputStream out = new FileOutputStream(dst);
				byte[] buffer = new byte[1024];
				InputStream in;
				int readLen = 0;
				for(int i=0;i<partFileList.length;i++){
				// 获得输入流 ,注意文件的路径
				in = c.getAssets().open(partFileList[i]);
				while((readLen = in.read(buffer)) != -1){
					out.write(buffer, 0, readLen);
				}
				out.flush();
				in.close();
				}
				// 把所有小文件都进行写操作后才关闭输出流，这样就会合并为一个文件了
				out.close();
			}
		} 
}

	Arrays.sort(data, new Comparator<Object>() {
				public int compare(Object arg0, Object arg1) {
					String str1 = (String) arg0;
					String str2 = (String) arg1;
					return Integer.parseInt(str1) - Integer.parseInt(str2);
				}
			});