1使用xutils3进行下载
2先实现下载一张图片到本地
3使用for循环实现多张图片

/**
* 文件下载地址
*/
String downloadUrl = "";

/**
* 下载文件的保存位置
*/
String saveFilePath = "";


//点击事件
mUpDataBt.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(final View v) {
final ProgressDialog dialog = new ProgressDialog(MainActivity.this);
dialog.setTitle("图片更新中");
dialog.show();
listImage.clear();
listImage = dbUtil.findPicName();
// 没有skuimg文件夹则创建skuimg
String sdPath = getExternalFilesDir(Environment.DIRECTORY_PICTURES) + "/skuimg";
File file = new File(sdPath);
if (!file.exists()) {
file.mkdirs();
Log.e("wy", "创建了skuimg文件夹");
}
new Thread() {
@Override
public void run() {
super.run();
for (int i = 0; i < listImage.size(); i++) {
Object imageString = listImage.get(i);
if (imageString != null) {
downloadUrl = Constant.BASE_URL + "/" + imageString;
saveFilePath = getExternalFilesDir(Environment.DIRECTORY_PICTURES) + "/" + imageString;
Log.e("wy", "saveFilePath: " + saveFilePath);
DownLoadUtil.DownLoadFile(downloadUrl, saveFilePath, new MyCallBack<File>() {

@Override
public void onSuccess(File result) {
super.onSuccess(result);

// DownLoadUtil.showToast(MainActivity.this, "下载成功");
}

@Override
public void onError(Throwable ex, boolean isOnCallback) {
super.onError(ex, isOnCallback);
dialog.dismiss();
Log.e("wy", "图片下载失败原因: " + ex.getMessage());
// DownLoadUtil.showToast(MainActivity.this, "下载失败");
}

});
}

}
Log.e("wy", "run: " + "下载图片成功");
dialog.dismiss();

}
}.start();


return true;
}
});
package com.wintec.huashang.utils;

import android.content.Context;
import android.widget.Toast;

import org.xutils.common.Callback;
import org.xutils.http.RequestParams;
import org.xutils.x;

public class DownLoadUtil {
/**
* 下载文件
*/
public static <T> Callback.Cancelable DownLoadFile(String url, String filepath, Callback.CommonCallback<T> callback) {
RequestParams params = new RequestParams(url);
//设置断点续传
params.setAutoResume(true);
params.setSaveFilePath(filepath);
Callback.Cancelable cancelable = x.http().get(params, callback);
return cancelable;
}

/**
* 单例吐司
*/
private static Toast toast;
public static void showToast(Context context, String msg) {
if (toast == null) {
toast = Toast.makeText(context, msg, Toast.LENGTH_SHORT);
}
toast.setText(msg);
toast.show();
}



}
package com.wintec.huashang.utils;

import org.xutils.common.Callback;

public class MyCallBack<ResultType> implements Callback.CommonCallback<ResultType> {

@Override
public void onSuccess(ResultType result) {
//根据需求进行请求成功的逻辑处理
}

@Override
public void onError(Throwable ex, boolean isOnCallback) {
//根据需求进行请求网络失败的逻辑处理
}

@Override
public void onCancelled(CancelledException cex) {

}

@Override
public void onFinished() {

}
}

查表中某一列的全部数据的sql语句

public ArrayList findPicName() {
ArrayList goodsList = new ArrayList();
// Cursor cursor = mSQLiteDatabase.rawQuery("select name from Person where searchKey like ? ", new String[]{"'%"+searchKey+"%'"});
Cursor cursor = mSQLiteDatabase.rawQuery("select previewImage from Person ", new String[]{});
int count = cursor.getCount();
Log.e("wy", "名称同类的数量: " + count);
for (int i = 0; i < count; i++) {
while (cursor.moveToNext()) {
// Log.e("wy","获取到分类商品: "+ cursor.getString(i));
String goods = cursor.getString(i);
goodsList.add(goods);
}
}
Log.e("wy", "集合大小为: " + goodsList.size());

cursor.close();
return goodsList;

}