Support file downloading in Java jersey2 client

modules/swagger-codegen/src/main/resources/Java/libraries/jersey2/ApiClient.mustache

@@ -20,6 +20,9 @@ import org.glassfish.jersey.media.multipart.FormDataContentDisposition;
 import org.glassfish.jersey.media.multipart.MultiPart;
 import org.glassfish.jersey.media.multipart.MultiPartFeature;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
@@ -37,6 +40,8 @@ import java.io.UnsupportedEncodingException;
 
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import {{invokerPackage}}.auth.Authentication;
 import {{invokerPackage}}.auth.HttpBasicAuth;
@@ -52,6 +57,7 @@ public class ApiClient {
 
   private Client httpClient;
   private JSON json;
+  private String tempFolderPath = null;
 
   private Map<String, Authentication> authentications;
 
@@ -236,8 +242,24 @@ public class ApiClient {
   }
 
   /**
-  * Connect timeout (in milliseconds).
-  */
+   * The path of temporary folder used to store downloaded files from endpoints
+   * with file response. The default value is <code>null</code>, i.e. using
+   * the system's default tempopary folder.
+   *
+   * @see https://docs.oracle.com/javase/7/docs/api/java/io/File.html#createTempFile(java.lang.String,%20java.lang.String,%20java.io.File)
+   */
+  public String getTempFolderPath() {
+    return tempFolderPath;
+  }
+
+  public ApiClient setTempFolderPath(String tempFolderPath) {
+    this.tempFolderPath = tempFolderPath;
+    return this;
+  }
+
+  /**
+   * Connect timeout (in milliseconds).
+   */
   public int getConnectTimeout() {
     return connectionTimeout;
   }
@@ -247,11 +269,11 @@ public class ApiClient {
    * A value of 0 means no timeout, otherwise values must be between 1 and
    * {@link Integer#MAX_VALUE}.
    */
-   public ApiClient setConnectTimeout(int connectionTimeout) {
-     this.connectionTimeout = connectionTimeout;
-     httpClient.property(ClientProperties.CONNECT_TIMEOUT, connectionTimeout);
-     return this;
-   }
+  public ApiClient setConnectTimeout(int connectionTimeout) {
+    this.connectionTimeout = connectionTimeout;
+    httpClient.property(ClientProperties.CONNECT_TIMEOUT, connectionTimeout);
+    return this;
+  }
 
   /**
    * Get the date format used to parse/format date parameters.
@@ -467,6 +489,13 @@ public class ApiClient {
    * Deserialize response body to Java object according to the Content-Type.
    */
   public <T> T deserialize(Response response, GenericType<T> returnType) throws ApiException {
+    // Handle file downloading.
+    if (returnType.equals(File.class)) {
+      @SuppressWarnings("unchecked")
+      T file = (T) downloadFileFromResponse(response);
+      return file;
+    }
+
     String contentType = null;
     List<Object> contentTypes = response.getHeaders().get("Content-Type");
     if (contentTypes != null && !contentTypes.isEmpty())
@@ -477,6 +506,55 @@ public class ApiClient {
     return response.readEntity(returnType);
   }
 
+  /**
+   * Download file from the given response.
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(Response response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      Files.copy(response.readEntity(InputStream.class), file.toPath());
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  public File prepareDownloadFile(Response response) throws IOException {
+    String filename = null;
+    String contentDisposition = (String) response.getHeaders().getFirst("Content-Disposition");
+    if (contentDisposition != null && !"".equals(contentDisposition)) {
+      // Get filename from the Content-Disposition header.
+      Pattern pattern = Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      Matcher matcher = pattern.matcher(contentDisposition);
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+
+    String prefix = null;
+    String suffix = null;
+    if (filename == null) {
+      prefix = "download-";
+      suffix = "";
+    } else {
+      int pos = filename.lastIndexOf(".");
+      if (pos == -1) {
+        prefix = filename + "-";
+      } else {
+        prefix = filename.substring(0, pos) + "-";
+        suffix = filename.substring(pos);
+      }
+      // File.createTempFile requires the prefix to be at least three characters long
+      if (prefix.length() < 3)
+        prefix = "download-";
+    }
+
+    if (tempFolderPath == null)
+      return File.createTempFile(prefix, suffix);
+    else
+      return File.createTempFile(prefix, suffix, new File(tempFolderPath));
+  }
+
   /**
    * Invoke API by sending HTTP request with the given options.
    *

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/ApiClient.java

@@ -20,6 +20,9 @@
 import org.glassfish.jersey.media.multipart.MultiPart;
 import org.glassfish.jersey.media.multipart.MultiPartFeature;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
@@ -37,13 +40,15 @@
 
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import io.swagger.client.auth.Authentication;
 import io.swagger.client.auth.HttpBasicAuth;
 import io.swagger.client.auth.ApiKeyAuth;
 import io.swagger.client.auth.OAuth;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-15T19:00:52.199+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class ApiClient {
   private Map<String, String> defaultHeaderMap = new HashMap<String, String>();
   private String basePath = "http://petstore.swagger.io/v2";
@@ -52,6 +57,7 @@ public class ApiClient {
 
   private Client httpClient;
   private JSON json;
+  private String tempFolderPath = null;
 
   private Map<String, Authentication> authentications;
 
@@ -235,8 +241,24 @@ public ApiClient setDebugging(boolean debugging) {
   }
 
   /**
-  * Connect timeout (in milliseconds).
-  */
+   * The path of temporary folder used to store downloaded files from endpoints
+   * with file response. The default value is <code>null</code>, i.e. using
+   * the system's default tempopary folder.
+   *
+   * @see https://docs.oracle.com/javase/7/docs/api/java/io/File.html#createTempFile(java.lang.String,%20java.lang.String,%20java.io.File)
+   */
+  public String getTempFolderPath() {
+    return tempFolderPath;
+  }
+
+  public ApiClient setTempFolderPath(String tempFolderPath) {
+    this.tempFolderPath = tempFolderPath;
+    return this;
+  }
+
+  /**
+   * Connect timeout (in milliseconds).
+   */
   public int getConnectTimeout() {
     return connectionTimeout;
   }
@@ -246,11 +268,11 @@ public int getConnectTimeout() {
    * A value of 0 means no timeout, otherwise values must be between 1 and
    * {@link Integer#MAX_VALUE}.
    */
-   public ApiClient setConnectTimeout(int connectionTimeout) {
-     this.connectionTimeout = connectionTimeout;
-     httpClient.property(ClientProperties.CONNECT_TIMEOUT, connectionTimeout);
-     return this;
-   }
+  public ApiClient setConnectTimeout(int connectionTimeout) {
+    this.connectionTimeout = connectionTimeout;
+    httpClient.property(ClientProperties.CONNECT_TIMEOUT, connectionTimeout);
+    return this;
+  }
 
   /**
    * Get the date format used to parse/format date parameters.
@@ -466,6 +488,13 @@ public Entity<?> serialize(Object obj, Map<String, Object> formParams, String co
    * Deserialize response body to Java object according to the Content-Type.
    */
   public <T> T deserialize(Response response, GenericType<T> returnType) throws ApiException {
+    // Handle file downloading.
+    if (returnType.equals(File.class)) {
+      @SuppressWarnings("unchecked")
+      T file = (T) downloadFileFromResponse(response);
+      return file;
+    }
+
     String contentType = null;
     List<Object> contentTypes = response.getHeaders().get("Content-Type");
     if (contentTypes != null && !contentTypes.isEmpty())
@@ -476,6 +505,55 @@ public <T> T deserialize(Response response, GenericType<T> returnType) throws Ap
     return response.readEntity(returnType);
   }
 
+  /**
+   * Download file from the given response.
+   * @throws ApiException If fail to read file content from response and write to disk
+   */
+  public File downloadFileFromResponse(Response response) throws ApiException {
+    try {
+      File file = prepareDownloadFile(response);
+      Files.copy(response.readEntity(InputStream.class), file.toPath());
+      return file;
+    } catch (IOException e) {
+      throw new ApiException(e);
+    }
+  }
+
+  public File prepareDownloadFile(Response response) throws IOException {
+    String filename = null;
+    String contentDisposition = (String) response.getHeaders().getFirst("Content-Disposition");
+    if (contentDisposition != null && !"".equals(contentDisposition)) {
+      // Get filename from the Content-Disposition header.
+      Pattern pattern = Pattern.compile("filename=['\"]?([^'\"\\s]+)['\"]?");
+      Matcher matcher = pattern.matcher(contentDisposition);
+      if (matcher.find())
+        filename = matcher.group(1);
+    }
+
+    String prefix = null;
+    String suffix = null;
+    if (filename == null) {
+      prefix = "download-";
+      suffix = "";
+    } else {
+      int pos = filename.lastIndexOf(".");
+      if (pos == -1) {
+        prefix = filename + "-";
+      } else {
+        prefix = filename.substring(0, pos) + "-";
+        suffix = filename.substring(pos);
+      }
+      // File.createTempFile requires the prefix to be at least three characters long
+      if (prefix.length() < 3)
+        prefix = "download-";
+    }
+
+    if (tempFolderPath == null)
+      return File.createTempFile(prefix, suffix);
+    else
+      return File.createTempFile(prefix, suffix, new File(tempFolderPath));
+  }
+
   /**
    * Invoke API by sending HTTP request with the given options.
    *

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/ApiException.java

@@ -3,7 +3,7 @@
 import java.util.Map;
 import java.util.List;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-05T14:39:17.660+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class ApiException extends Exception {
   private int code = 0;
   private Map<String, List<String>> responseHeaders = null;

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/Configuration.java

@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-05T14:39:17.660+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class Configuration {
   private static ApiClient defaultApiClient = new ApiClient();
 

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/JSON.java

@@ -8,7 +8,7 @@
 
 import javax.ws.rs.ext.ContextResolver;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-05T14:39:17.660+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class JSON implements ContextResolver<ObjectMapper> {
   private ObjectMapper mapper;
 

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/Pair.java

@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-05T14:39:17.660+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class Pair {
     private String name = "";
     private String value = "";

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/StringUtil.java

@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-05T14:39:17.660+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class StringUtil {
   /**
    * Check if the given array contains the given value (with case-insensitive comparison).

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/api/PetApi.java

@@ -12,7 +12,7 @@
 
 import java.util.*;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-15T19:00:52.199+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class PetApi {
   private ApiClient apiClient;
 

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/api/StoreApi.java

@@ -12,7 +12,7 @@
 
 import java.util.*;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-05T14:39:17.660+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class StoreApi {
   private ApiClient apiClient;
 

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/api/UserApi.java

@@ -12,7 +12,7 @@
 
 import java.util.*;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-05T14:39:17.660+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class UserApi {
   private ApiClient apiClient;
 

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/auth/ApiKeyAuth.java

@@ -5,7 +5,7 @@
 import java.util.Map;
 import java.util.List;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-05T14:39:17.660+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class ApiKeyAuth implements Authentication {
   private final String location;
   private final String paramName;

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/auth/HttpBasicAuth.java

@@ -9,7 +9,7 @@
 
 import java.io.UnsupportedEncodingException;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-05T14:39:17.660+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class HttpBasicAuth implements Authentication {
   private String username;
   private String password;

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/auth/OAuth.java

@@ -5,7 +5,7 @@
 import java.util.Map;
 import java.util.List;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-05T14:39:17.660+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class OAuth implements Authentication {
   private String accessToken;
 

samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Category.java

@@ -10,7 +10,7 @@
 
 
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-15T19:00:52.199+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-01-28T16:23:25.238+01:00")
 public class Category   {
 
   private Long id = null;