使用Okhttp 上传图像

• 1. 首先添加依赖和权限

依赖：

            implementation 'com.android.support:design:27.1.1'  //防止版本错误
            implementation 'com.github.bumptech.glide:glide:3.8.0'      //解析图片（glide图片加载框架）
            implementation 'com.squareup.picasso:picasso:2.3.2'     //解析图片
            implementation 'com.squareup.okhttp3:okhttp:3.10.0'//okhttp3
            implementation 'com.google.code.gson:gson:2.2.4'//gson

权限：

            <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
            <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
            <uses-permission android:name="android.permission.INTERNET"/>

• 2.在activity_main.xml文件中写布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="上传文件" />

    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <ImageView
        android:id="@+id/img"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout> 

• 3.在MainActivity.java 文件中实现效果

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    /**
     * 上传文件
     */
    private Button mBtn;
    private TextView mText;
    private ImageView mImg;
    private File mFile;
    private String url = "http://yun918.cn/study/public/file_upload.php";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        mBtn = (Button) findViewById(R.id.btn);
        mBtn.setOnClickListener(this);
        mText = (TextView) findViewById(R.id.text);
        mImg = (ImageView) findViewById(R.id.img);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            default:
                break;
            case R.id.btn:
                initData();
                break;
        }
    }

    private void initData() {

        // 判断是否有写入数据的权限
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
                == PackageManager.PERMISSION_GRANTED) {
            uploadFile();
        } else {
            // 获取（请求）权限
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission
                    .WRITE_EXTERNAL_STORAGE}, 1);
        }
    }

    /**
     * 请求结果
     * @param requestCode
     * @param permissions
     * @param grantResults
     */
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        
        // 用户是否获取权限
        if (requestCode == 1 && grantResults.length > 0 && grantResults[0] == PackageManager
                .PERMISSION_GRANTED) {
            uploadFile();
        } else {
            Toast.makeText(this, "授权失败", Toast.LENGTH_SHORT).show();
        }
    }




    private void uploadFile() {

        // 获取要上传的文件
        mFile = new File("/storage/sdcard0/Pictures/text.jpg");

       /* if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
            File directory = Environment.getExternalStorageDirectory();
            mFile = new File(directory, "text.jpg");
        }*/


        OkHttpClient client = new OkHttpClient.Builder()
                .build();

        // 设置文件以及文件上传类型封装
        RequestBody requestBody = RequestBody.create(MediaType.parse("image/jpg"), mFile);
        
        // 文件上传的请求体封装
        MultipartBody multipartBody = new MultipartBody.Builder()
                .setType(MultipartBody.FORM)
                .addFormDataPart("key", "H1808C")
                .addFormDataPart("file", mFile.getName(), requestBody)
                .build();

        Request request = new Request.Builder()
                .url("http://yun918.cn/study/public/file_upload.php")
                .post(multipartBody)
                .build();


        Call call = client.newCall(request);

        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {

                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(MainActivity.this, e.getMessage(), Toast.LENGTH_SHORT).show();
                    }
                });
            
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {

                final String result = response.body().string();

                Gson gson = new Gson();
                final UpLoadBean upLoadBean = gson.fromJson(result, UpLoadBean.class);

                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {

                      
                        if (upLoadBean != null) {

                            if (upLoadBean.getCode() == 200) {

                                mText.setText(upLoadBean.getRes());

                                Glide.with(MainActivity.this).load(upLoadBean.getData().getUrl()).into(mImg);


                            } else {

                                mText.setText(upLoadBean.getRes());

                            }


                        } else {

                            Toast.makeText(MainActivity.this, "失败", Toast.LENGTH_SHORT).show();
                        }

                    }
                });


            }
        });


    }
}

• 4.bean文件夹下的实体类

public class UpLoadBean {


    /**
     * code : 200
     * res : 上传文件成功
     * data : {"url":"http://yun918.cn/study/public/uploadfiles/abc/b.jpg"}
     */

    private int code;
    private String res;
    private DataBean data;

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getRes() {
        return res;
    }

    public void setRes(String res) {
        this.res = res;
    }

    public DataBean getData() {
        return data;
    }

    public void setData(DataBean data) {
        this.data = data;
    }

    public static class DataBean {
        /**
         * url : http://yun918.cn/study/public/uploadfiles/abc/b.jpg
         */

        private String url;

        public String getUrl() {
            return url;
        }

        public void setUrl(String url) {
            this.url = url;
        }
    }
}