Add endpoint to download a zip file

src/main/java/com/wilkins/showcase/controllers/DocumentController.java

@@ -0,0 +1,67 @@
+package com.wilkins.showcase.controllers;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.ContentDisposition;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.List;
+import java.util.UUID;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
+
+import static org.springframework.http.ResponseEntity.ok;
+
+@RestController
+@RequestMapping("/documents")
+public class DocumentController {
+
+    private static final Logger log = LoggerFactory.getLogger(DocumentController.class);
+
+    @GetMapping(produces = "application/zip")
+    public ResponseEntity<StreamingResponseBody> download() {
+        return ok()
+                .header(HttpHeaders.CONTENT_DISPOSITION,
+                        ContentDisposition.builder("zipfile").filename("documents.zip").build().toString())
+                .body(DocumentController::asZipFile);
+    }
+
+    private static void asZipFile(OutputStream outputStream) throws IOException {
+        try (var zip = new ZipOutputStream(outputStream)) {
+            files().forEach(file -> addToZip(file, zip));
+        }
+    }
+
+    private static List<String> files() {
+        return List.of("src/main/resources/test-doc-one.pdf",
+                "src/main/resources/test-doc-two.pdf");
+    }
+
+    private static void addToZip(String file, ZipOutputStream zip) {
+        var zipEntry = new ZipEntry(name());
+        try {
+            zip.putNextEntry(zipEntry);
+            readFileAndSendTo(zip, file);
+        } catch (IOException e) {
+            log.error("Exception adding files to zip", e);
+        }
+    }
+
+    private static void readFileAndSendTo(OutputStream outputStream, String fileName) throws IOException {
+        try (var inputStream = new FileInputStream(fileName)) {
+            inputStream.transferTo(outputStream);
+        }
+    }
+
+    private static String name() {
+        return UUID.randomUUID() + ".pdf";
+    }
+}

src/main/java/com/wilkins/showcase/controllers/GreetingController.java

@@ -13,7 +13,7 @@ public class GreetingController {
 
     @GetMapping("/greeting")
     public Greeting getGreeting(@RequestParam(name = "salutation", required = false, defaultValue = "hello") String salutationParam,
-                               @RequestParam(name = "name", required = false, defaultValue = "world") String nameParam) {
+                                @RequestParam(name = "name", required = false, defaultValue = "world") String nameParam) {
 
         log.info("A greeting was requested");
 

src/test/java/com/wilkins/showcase/controllers/DocumentControllerTest.java

@@ -0,0 +1,25 @@
+package com.wilkins.showcase.controllers;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.result.MockMvcResultMatchers;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@WebMvcTest(controllers = DocumentController.class)
+public class DocumentControllerTest {
+
+    @Autowired
+    MockMvc mockMvc;
+
+    @Test
+    void returnsZipFile() throws Exception {
+        mockMvc.perform(get("/documents"))
+                .andExpect(status().isOk())
+                .andExpect(MockMvcResultMatchers.header().string("Content-Disposition", is("zipfile; filename=\"documents.zip\"")));
+    }
+}

src/test/java/com/wilkins/showcase/controllers/GreetingControllerTest.java

@@ -10,7 +10,7 @@
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
-@WebMvcTest
+@WebMvcTest(controllers = GreetingController.class)
 public class GreetingControllerTest {
 
     @Autowired
@@ -23,5 +23,4 @@ void returnsGreeting() throws Exception {
                 .andExpect(jsonPath("$.salutation", is("hello")))
                 .andExpect(jsonPath("$.name", is("world")));
     }
-
 }