Android 拍照选择图片并上传功能的实现思路(包含权限动态获取)

作为一个Android新手，想实现手机拍照并上传的功能，经过查找资料，已实现此功能。在此记录备忘。老鸟请忽略。

一、实现思路：

1.Android手机客户端，拍照(或选择图片)，然后上传到服务器。

2.服务器端接收手机端上传上来的图片。

二、实现步骤：

1.按惯例，先放效果图：

项目结构：

2.activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical"
 android:padding="5dp">

 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="图片预览" />

 <ImageView
 android:id="@+id/imageView"
 android:layout_width="match_parent"
 android:layout_height="400dp"
 android:background="#fff"
 android:padding="1dp"
 android:scaleType="fitXY" />

 <LinearLayout
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center_horizontal"
 android:orientation="horizontal">

 <Button
 android:id="@+id/btnPhoto"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="拍照" />

 <Button
 android:id="@+id/btnSelect"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="选择" />
 </LinearLayout>
</LinearLayout>

3.MainActivity.java

package com.qingshan.note;
import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import android.Manifest;
import android.app.AlertDialog;
import android.content.ContentValues;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.provider.Settings;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
 private Button btnPhoto, btnSelect;
 private Intent intent;
 private final int CAMERA = 1;//事件枚举(可以自定义)
 private final int CHOOSE = 2;//事件枚举(可以自定义)
 private final String postUrl = "http://qingshanboke.com/Home/AndoridUploadFile";//接收上传图片的地址
 String photoPath = "";//要上传的图片路径
 private final int permissionCode = 100;//权限请求码
 //权限集合，对应在AndroidManifest.xml文件中添加配置
 // <uses-permission android:name="android.permission.CAMERA" />
 // <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 // <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 // <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
 // <uses-permission android:name="android.permission.INTERNET"/>
 String[] permissions = new String[]{
 Manifest.permission.CAMERA,
 Manifest.permission.WRITE_EXTERNAL_STORAGE,
 Manifest.permission.ACCESS_NETWORK_STATE,
 Manifest.permission.ACCESS_WIFI_STATE,
 Manifest.permission.INTERNET
 };
 AlertDialog alertDialog;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 //6.0才用动态权限
 if (Build.VERSION.SDK_INT >= 23) {
 checkPermission();
 }
 btnPhoto = findViewById(R.id.btnPhoto);
 btnSelect = findViewById(R.id.btnSelect);
 btnPhoto.setOnClickListener(this);
 btnSelect.setOnClickListener(this);
 }
 //检查权限
 private void checkPermission() {
 List<String> permissionList = new ArrayList<>();
 for (int i = 0; i < permissions.length; i++) {
 if (ContextCompat.checkSelfPermission(this, permissions[i]) != PackageManager.PERMISSION_GRANTED) {
 permissionList.add(permissions[i]);
 }
 }
 if (permissionList.size() <= 0) {
 //说明权限都已经通过，可以做你想做的事情去
 } else {
 //存在未允许的权限
 ActivityCompat.requestPermissions(this, permissions, permissionCode);
 }
 }
 //授权后回调函数
 @Override
 public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
 super.onRequestPermissionsResult(requestCode, permissions, grantResults);
 boolean haspermission = false;
 if (permissionCode == requestCode) {
 for (int i = 0; i < grantResults.length; i++) {
 if (grantResults[i] == -1) {
 haspermission = true;
 }
 }
 if (haspermission) {
 //跳转到系统设置权限页面，或者直接关闭页面，不让他继续访问
 permissionDialog();
 } else {
 //全部权限通过，可以进行下一步操作
 }
 }
 }
 //打开手动设置应用权限
 private void permissionDialog() {
 if (alertDialog == null) {
 alertDialog = new AlertDialog.Builder(this)
 .setTitle("提示信息")
 .setMessage("当前应用缺少必要权限，该功能暂时无法使用。如若需要，请单击【确定】按钮前往设置中心进行权限授权。")
 .setPositiveButton("设置", new DialogInterface.OnClickListener() {
 @Override
 public void onClick(DialogInterface dialog, int which) {
 cancelPermissionDialog();
 Uri packageURI = Uri.parse("package:" + getPackageName());
 Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS, packageURI);
 startActivity(intent);
 }
 })
 .setNegativeButton("取消", new DialogInterface.OnClickListener() {
 @Override
 public void onClick(DialogInterface dialog, int which) {
 cancelPermissionDialog();
 }
 })
 .create();
 }
 alertDialog.show();
 }
 //用户取消授权
 private void cancelPermissionDialog() {
 alertDialog.cancel();
 }
 @Override
 public void onClick(View v) {
 switch (v.getId()) {
 //拍照按钮事件
 case R.id.btnPhoto:
 //方法一：这样拍照只能取到缩略图（不清晰）
 //intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
 //startActivityForResult(intent, CAMERA);
 //方法二：指定加载路径图片路径（保存原图，清晰）
 String SD_PATH = Environment.getExternalStorageDirectory().getPath() + "/拍照上传示例/";
 SimpleDateFormat format = new SimpleDateFormat("yyyyMMddHHmmss");
 String fileName = format.format(new Date(System.currentTimeMillis())) + ".JPEG";
 photoPath = SD_PATH + fileName;
 File file = new File(photoPath);
 if (!file.getParentFile().exists()) {
 file.getParentFile().mkdirs();
 }
 //兼容7.0以上的版本
 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
 try {
 ContentValues values = new ContentValues(1);
 values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpg");
 values.put(MediaStore.Images.Media.DATA, photoPath);
 Uri tempuri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
 Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
 intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
 if (tempuri != null) {
 intent.putExtra(MediaStore.EXTRA_OUTPUT, tempuri);
 intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1);
 }
 startActivityForResult(intent, CAMERA);
 } catch (Exception e) {
 e.printStackTrace();
 }
 } else {
 intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
 Uri uri = Uri.fromFile(file);
 intent.putExtra(MediaStore.EXTRA_OUTPUT, uri); //指定拍照后的存储路径，保存原图
 startActivityForResult(intent, CAMERA);
 }
 break;
 //选择按钮事件
 case R.id.btnSelect:
 intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
 startActivityForResult(intent, CHOOSE);
 break;
 }
 }
 @RequiresApi(api = Build.VERSION_CODES.O)
 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
 super.onActivityResult(requestCode, resultCode, data);
 switch (requestCode) {
 // 调用照相机拍照
 case CAMERA:
 if (resultCode == RESULT_OK) {
 //对应方法一：图片未保存，需保存文件到本地
// Bundle bundle = data.getExtras();
// Bitmap bitmap = (Bitmap) bundle.get("data");
// String savePath;
// String SD_PATH = Environment.getExternalStorageDirectory().getPath() + "/拍照上传示例/";
// SimpleDateFormat format = new SimpleDateFormat("yyyyMMddHHmmss");
// String fileName = format.format(new Date(System.currentTimeMillis())) + ".JPEG";
// if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
// savePath = SD_PATH;
// } else {
// Toast.makeText(MainActivity.this, "保存失败！", Toast.LENGTH_SHORT).show();
// return;
// }
// photoPath = savePath + fileName;
// File file = new File(photoPath);
// try {
// if (!file.exists()) {
// file.getParentFile().mkdirs();
// file.createNewFile();
// }
// FileOutputStream stream = new FileOutputStream(file);
// bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
// Toast.makeText(MainActivity.this, "保存成功,位置:" + file.getAbsolutePath(), Toast.LENGTH_SHORT).show();
// } catch (IOException e) {
// e.printStackTrace();
// }
 //对应方法二：图片已保存，只需读取就行了
 try {
 FileInputStream stream = new FileInputStream(photoPath);
 Bitmap bitmap = BitmapFactory.decodeStream(stream);
 //预览图片
 ImageView image = findViewById(R.id.imageView);
 image.setImageBitmap(bitmap);
 //上传图片（Android 4.0 之后不能在主线程中请求HTTP请求）
 File file = new File(photoPath);
 if (file.exists()) {
 new Thread(new Runnable() {
 @Override
 public void run() {
  //文本字段（用于验证用户身份）
  HashMap<String, String> form = new HashMap<String, String>();
  form.put("username", "zhangqs");
  form.put("password", "123456");
  //图片字段
  HashMap<String, String> file = new HashMap<String, String>();
  file.put(PathHelper.getFileNameFromPath(photoPath), photoPath);
  formUpload(postUrl, form, file);
 }
 }).start();
 }
 } catch (FileNotFoundException e) {
 e.printStackTrace();
 }
 }
 break;
 // 选择图片库的图片
 case CHOOSE:
 if (resultCode == RESULT_OK) {
 try {
 Uri uri = data.getData();
 photoPath = PathHelper.getRealPathFromUri(MainActivity.this, uri);
 Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), uri);
 //压缩图片
 bitmap = scaleBitmap(bitmap, (float) 0.5);
 //预览图片
 ImageView image = findViewById(R.id.imageView);
 image.setImageBitmap(bitmap);
 //上传图片（Android 4.0 之后不能在主线程中请求HTTP请求）
 File file = new File(photoPath);
 if (file.exists()) {
 new Thread(new Runnable() {
 @Override
 public void run() {
  //文本字段（用于验证用户身份）
  HashMap<String, String> form = new HashMap<String, String>();
  form.put("username", "zhangqs");
  form.put("password", "123456");
  //图片字段
  HashMap<String, String> file = new HashMap<String, String>();
  file.put(PathHelper.getFileNameFromPath(photoPath), photoPath);
  formUpload(postUrl, form, file);
 }
 }).start();
 }
 } catch (IOException e) {
 e.printStackTrace();
 }
 }
 break;
 }
 }
 //压缩图片
 public Bitmap scaleBitmap(Bitmap origin, float ratio) {
 if (origin == null) {
 return null;
 }
 int width = origin.getWidth();
 int height = origin.getHeight();
 Matrix matrix = new Matrix();
 matrix.preScale(ratio, ratio);
 Bitmap newBM = Bitmap.createBitmap(origin, 0, 0, width, height, matrix, false);
 return newBM;
 }
 //POST 表单提交
 @RequiresApi(api = Build.VERSION_CODES.O)
 public static String formUpload(String posturl, Map<String, String> textMap, Map<String, String> fileMap) {
 String res = "";
 HttpURLConnection conn = null;
 String BOUNDARY = "---------------------------123821742118716"; //boundary就是request头和上传文件内容的分隔符
 try {
 URL url = new URL(posturl);
 conn = (HttpURLConnection) url.openConnection();
 conn.setConnectTimeout(5000);
 conn.setReadTimeout(30000);
 conn.setDoOutput(true);
 conn.setDoInput(true);
 conn.setUseCaches(false);
 conn.setRequestMethod("POST");
 conn.setRequestProperty("Connection", "Keep-Alive");
 conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 6.1; zh-CN; rv:1.9.2.6)");
 conn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + BOUNDARY);
 OutputStream out = new DataOutputStream(conn.getOutputStream());
 // text
 if (textMap != null) {
 StringBuffer buffer = new StringBuffer();
 Iterator iter = textMap.entrySet().iterator();
 while (iter.hasNext()) {
 Map.Entry entry = (Map.Entry) iter.next();
 String inputName = (String) entry.getKey();
 String inputValue = (String) entry.getValue();
 if (inputValue == null) {
 continue;
 }
 buffer.append("\r\n").append("--").append(BOUNDARY).append("\r\n");
 buffer.append("Content-Disposition: form-data; name=\"" + inputName + "\"\r\n\r\n");
 buffer.append(inputValue);
 }
 out.write(buffer.toString().getBytes());
 }
 // file
 if (fileMap != null) {
 Iterator iter = fileMap.entrySet().iterator();
 while (iter.hasNext()) {
 Map.Entry entry = (Map.Entry) iter.next();
 String inputName = (String) entry.getKey();
 String inputValue = (String) entry.getValue();
 if (inputValue == null) {
 continue;
 }
 File file = new File(inputValue);
 String filename = file.getName();
 String contentType = "";
 if (filename.endsWith(".jpg")) {
 contentType = "image/jpg";
 } else if (filename.endsWith(".png")) {
 contentType = "image/png";
 } else if (contentType == null || contentType.equals("")) {
 contentType = "application/octet-stream";
 }
 StringBuffer buffer = new StringBuffer();
 buffer.append("\r\n").append("--").append(BOUNDARY).append("\r\n");
 buffer.append("Content-Disposition: form-data; name=\"" + inputName + "\"; filename=\"" + filename + "\"\r\n");
 buffer.append("Content-Type:" + contentType + "\r\n\r\n");
 out.write(buffer.toString().getBytes());
 DataInputStream in = new DataInputStream(new FileInputStream(file));
 int bytes = 0;
 byte[] bufferOut = new byte[1024];
 while ((bytes = in.read(bufferOut)) != -1) {
 out.write(bufferOut, 0, bytes);
 }
 in.close();
 }
 }
 byte[] endData = ("\r\n--" + BOUNDARY + "--\r\n").getBytes();
 out.write(endData);
 out.flush();
 out.close();
 // 读取返回数据
 StringBuffer buffer = new StringBuffer();
 BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
 String line = null;
 while ((line = reader.readLine()) != null) {
 buffer.append(line).append("\n");
 }
 res = buffer.toString();
 reader.close();
 reader = null;
 } catch (Exception e) {
 System.out.println("发送POST请求出错。" + posturl);
 e.printStackTrace();
 } finally {
 if (conn != null) {
 conn.disconnect();
 conn = null;
 }
 }
 return res;
 }
}

4.辅助类 PathHelper.java

package com.qingshan.note;
import android.annotation.SuppressLint;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
//Android 路径辅助类
public class PathHelper {
 //适配api19以下(不包括api19),根据uri获取图片的绝对路径
 public static String getRealPathFromUri(Context context, Uri uri) {
 int sdkVersion = Build.VERSION.SDK_INT;
 if (sdkVersion >= 19) { // api >= 19
 return getRealPathFromUriAboveApi19(context, uri);
 } else { // api < 19
 return getRealPathFromUriBelowAPI19(context, uri);
 }
 }
 /**
 * 适配api19以下(不包括api19),根据uri获取图片的绝对路径
 *
 * @param context 上下文对象
 * @param uri 图片的Uri
 * @return 如果Uri对应的图片存在, 那么返回该图片的绝对路径, 否则返回null
 */
 private static String getRealPathFromUriBelowAPI19(Context context, Uri uri) {
 return getDataColumn(context, uri, null, null);
 }
 /**
 * 适配api19及以上,根据uri获取图片的绝对路径
 *
 * @param context 上下文对象
 * @param uri 图片的Uri
 * @return 如果Uri对应的图片存在, 那么返回该图片的绝对路径, 否则返回null
 */
 @SuppressLint("NewApi")
 private static String getRealPathFromUriAboveApi19(Context context, Uri uri) {
 String filePath = null;
 if (DocumentsContract.isDocumentUri(context, uri)) {
 // 如果是document类型的 uri, 则通过document id来进行处理
 String documentId = DocumentsContract.getDocumentId(uri);
 if (isMediaDocument(uri)) { // MediaProvider
 // 使用':'分割
 String id = documentId.split(":")[1];
 String selection = MediaStore.Images.Media._ID + "=?";
 String[] selectionArgs = {id};
 filePath = getDataColumn(context, MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection, selectionArgs);
 } else if (isDownloadsDocument(uri)) { // DownloadsProvider
 Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(documentId));
 filePath = getDataColumn(context, contentUri, null, null);
 }
 } else if ("content".equalsIgnoreCase(uri.getScheme())) {
 // 如果是 content 类型的 Uri
 filePath = getDataColumn(context, uri, null, null);
 } else if ("file".equals(uri.getScheme())) {
 // 如果是 file 类型的 Uri,直接获取图片对应的路径
 filePath = uri.getPath();
 }
 return filePath;
 }
 private static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
 String path = null;
 String[] projection = new String[]{MediaStore.Images.Media.DATA};
 Cursor cursor = null;
 try {
 cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
 if (cursor != null && cursor.moveToFirst()) {
 int columnIndex = cursor.getColumnIndexOrThrow(projection[0]);
 path = cursor.getString(columnIndex);
 }
 } catch (Exception e) {
 e.printStackTrace();
 } finally {
 if (cursor != null) {
 cursor.close();
 }
 }
 return path;
 }
 private static boolean isMediaDocument(Uri uri) {
 return "com.android.providers.media.documents".equals(uri.getAuthority());
 }
 private static boolean isDownloadsDocument(Uri uri) {
 return "com.android.providers.downloads.documents".equals(uri.getAuthority());
 }
 //从路径中提取文件名
 public static String getFileNameFromPath(String path) {
 int start = path.lastIndexOf("/");
 int end = path.lastIndexOf(".");
 if (start != -1 && end != -1) {
 return path.substring(start + 1, end);
 } else {
 return null;
 }
 }
}

5.AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.qingshan.note">
 <!-- 因为拍照需要写入文件 所以需要申请读取内存的权限 -->
 <uses-permission android:name="android.permission.CAMERA" />
 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
 <uses-permission android:name="android.permission.INTERNET"/>
 <application
 android:networkSecurityConfig="@xml/network_security_config"
 android:allowBackup="true"
 android:icon="@mipmap/ic_launcher"
 android:label="@string/app_name"
 android:usesCleartextTraffic="true"
 android:roundIcon="@mipmap/ic_launcher_round"
 android:supportsRtl="true"
 android:theme="@style/AppTheme">
 <activity android:name=".MainActivity">
 <intent-filter>
 <action android:name="android.intent.action.MAIN" />
 <category android:name="android.intent.category.LAUNCHER" />
 </intent-filter>
 </activity>
 </application>
</manifest>

6.\res\xml\network_security_config.xml

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
 <base-config cleartextTrafficPermitted="true" />
 <domain-config cleartextTrafficPermitted="true" >
 <domain includeSubdomains="true">127.0.0.1</domain>
 <domain includeSubdomains="true">192.168.100.192</domain>
 <domain includeSubdomains="true">localhost</domain>
 <domain includeSubdomains="true">qingshanboke.com</domain>
 </domain-config>
</network-security-config>

7.服务器端接收（asp.net mvc 接收）

public ActionResult AndoridUploadFile()
 {
 var userName = Request.Params["username"];
 var password = Request.Params["password"];
 if (string.IsNullOrEmpty(userName) || string.IsNullOrEmpty(password))
 {
 return Content("抱歉，用户名和密码错误！");
 }
 //todo:身份验证

 var dir = PathHelper.GetMapPath("~/Uploadfiles/" + DateTime.Now.ToString("yyyy-MM"));
 if (!Directory.Exists(dir))
 {
 Directory.CreateDirectory(dir);
 }
 for (int i = 0; i < Request.Files.Count; i++)
 {
 var path = Path.Combine(dir, DateTime.Now.ToString("yyyyMMddHHmmss") + ".jpg");
 if (Request.Files[i] != null)
 {
 Request.Files[i].SaveAs(path);
 }
 }
 return Content("{\"isSuccess\":true}");
 }

三、注意事项

1.Android发起http请求时，默认请求地址需https，需要增加 network-security-config 配置来允许使用http。（详见上面6.\res\xml\network_security_config.xml）

2.发起post提交时，往往需要做接口身份识别，需要将文本字段和图片字段一起提交，构造表单时，需要 "Content-Type", "multipart/form-data; boundary..."。

3.拍照时，默认只能取到缩略图，不够清晰，若要取到原图，需要在拍照时，传入指定保存位置，在回调函数中只需读取就可以了。

总结

以上所述是小编给大家介绍的Android 拍照选择图片并上传功能的实现思路(包含权限动态获取)，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对我们网站的支持！
如果你觉得本文对你有帮助，欢迎转载，烦请注明出处，谢谢！