Simplify link building

scm-webapp/src/main/java/sonia/scm/api/rest/resources/LinkBuilder.java

@@ -0,0 +1,90 @@
+package sonia.scm.api.rest.resources;
+
+import javax.ws.rs.core.UriBuilder;
+import javax.ws.rs.core.UriInfo;
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+class LinkBuilder {
+  private final UriInfo uriInfo;
+  private final Class[] classes;
+  private final List<Call> calls;
+
+  LinkBuilder(UriInfo uriInfo, Class... classes) {
+    this(uriInfo, classes, Collections.emptyList());
+  }
+
+  private LinkBuilder(UriInfo uriInfo, Class[] classes, List<Call> calls) {
+    this.uriInfo = uriInfo;
+    this.classes = classes;
+    this.calls = calls;
+  }
+
+
+  public Parameters method(String method) {
+    if (calls.size() >= classes.length) {
+      throw new IllegalStateException("no more classes for methods");
+    }
+    return new Parameters(method);
+  }
+
+  class Parameters {
+
+    private final String method;
+
+    private Parameters(String method) {
+      this.method = method;
+    }
+
+    public LinkBuilder parameters(String... parameters) {
+      return LinkBuilder.this.add(method, parameters);
+    }
+  }
+
+  private LinkBuilder add(String method, String[] parameters) {
+    List<Call> newCalls = new ArrayList<>(this.calls);
+    newCalls.add(new Call(LinkBuilder.this.classes[calls.size()], method, parameters));
+    return new LinkBuilder(uriInfo, classes, newCalls);
+  }
+
+  public Link create() {
+    if (calls.size() < classes.length) {
+      throw new IllegalStateException("not enough methods for all classes");
+    }
+
+    URI baseUri = uriInfo.getBaseUri();
+    URI relativeUri = createRelativeUri();
+    URI absoluteUri = baseUri.resolve(relativeUri);
+    return new Link(absoluteUri);
+  }
+
+  private URI createRelativeUri() {
+    UriBuilder uriBuilder = userUriBuilder();
+    calls.forEach(call -> uriBuilder.path(call.clazz, call.method));
+    String[] concatenatedParameters = calls
+      .stream()
+      .map(call -> call.parameters)
+      .flatMap(Arrays::stream)
+      .toArray(String[]::new);
+    return uriBuilder.build(concatenatedParameters);
+  }
+
+  private UriBuilder userUriBuilder() {
+    return UriBuilder.fromResource(classes[0]);
+  }
+
+  private static class Call {
+    private final Class clazz;
+    private final String method;
+    private final String[] parameters;
+
+    private Call(Class clazz, String method, String[] parameters) {
+      this.clazz = clazz;
+      this.method = method;
+      this.parameters = parameters;
+    }
+  }
+}

scm-webapp/src/main/java/sonia/scm/api/rest/resources/LinkMapBuilder.java

@@ -1,108 +0,0 @@
-package sonia.scm.api.rest.resources;
-
-import javax.ws.rs.core.UriBuilder;
-import javax.ws.rs.core.UriInfo;
-import java.net.URI;
-import java.util.*;
-
-class LinkMapBuilder {
-  private final UriInfo uriInfo;
-  private final Class[] classes;
-  private final Map<String, Link> links = new LinkedHashMap<>();
-
-  LinkMapBuilder(UriInfo uriInfo, Class... classes) {
-    this.uriInfo = uriInfo;
-    this.classes = classes;
-  }
-
-  Builder add(String linkName) {
-    return new ConcreteBuilder(linkName);
-  }
-
-  interface Builder {
-    Parameters method(String method);
-  }
-
-  interface Parameters {
-    Builder parameters(String... parameters);
-  }
-
-  private class ConcreteBuilder implements Builder {
-
-    private final String linkName;
-    private final List<Call> calls = new LinkedList<>();
-
-    private int callCount = 0;
-
-    ConcreteBuilder(String linkName) {
-      this.linkName = linkName;
-    }
-
-    public Parameters method(String method) {
-      return new ParametersImpl(method);
-    }
-
-    private class ParametersImpl implements Parameters {
-
-      private final String method;
-
-      ParametersImpl(String method) {
-        this.method = method;
-      }
-
-      public Builder parameters(String... parameters) {
-        return ConcreteBuilder.this.add(method, parameters);
-      }
-    }
-
-    private Builder add(String method, String[] parameters) {
-      this.calls.add(new Call(LinkMapBuilder.this.classes[callCount], method, parameters));
-      ++callCount;
-      if (callCount >= classes.length) {
-        links.put(linkName, createLink());
-        return x -> {
-          throw new IllegalStateException("no more classes for methods");
-        };
-      }
-      return this;
-    }
-
-    private Link createLink() {
-      URI baseUri = uriInfo.getBaseUri();
-      URI relativeUri = createRelativeUri();
-      URI absoluteUri = baseUri.resolve(relativeUri);
-      return new Link(absoluteUri);
-    }
-
-    private URI createRelativeUri() {
-      UriBuilder uriBuilder = userUriBuilder();
-      calls.forEach(call -> uriBuilder.path(call.clazz, call.method));
-      String[] concatenatedParameters = calls
-        .stream()
-        .map(call -> call.parameters)
-        .flatMap(Arrays::stream)
-        .toArray(String[]::new);
-      return uriBuilder.build(concatenatedParameters);
-    }
-
-    private UriBuilder userUriBuilder() {
-      return UriBuilder.fromResource(classes[0]);
-    }
-  }
-
-  Map<String, Link> getLinkMap() {
-    return Collections.unmodifiableMap(links);
-  }
-
-  private static class Call {
-    private final Class clazz;
-    private final String method;
-    private final String[] parameters;
-
-    private Call(Class clazz, String method, String[] parameters) {
-      this.clazz = clazz;
-      this.method = method;
-      this.parameters = parameters;
-    }
-  }
-}

scm-webapp/src/main/java/sonia/scm/api/rest/resources/User2UserDtoMapper.java

@@ -24,17 +24,15 @@ public abstract class User2UserDtoMapper {
 
   @AfterMapping
   void appendLinks(@MappingTarget UserDto target, @Context UriInfo uriInfo) {
-    LinkMapBuilder userLinkBuilder = new LinkMapBuilder(uriInfo, UserNewResource.class, UserSubResource.class);
-    LinkMapBuilder collectionLinkBuilder = new LinkMapBuilder(uriInfo, UserNewResource.class, UserCollectionResource.class);
-    userLinkBuilder.add("self").method("getUserSubResource").parameters(target.getName()).method("get").parameters();
+    LinkBuilder userLinkBuilder = new LinkBuilder(uriInfo, UserNewResource.class, UserSubResource.class);
+    LinkBuilder collectionLinkBuilder = new LinkBuilder(uriInfo, UserNewResource.class, UserCollectionResource.class);
+    Map<String, Link> links = new HashMap<>();
+    links.put("self", userLinkBuilder.method("getUserSubResource").parameters(target.getName()).method("get").parameters().create());
     if (SecurityUtils.getSubject().hasRole(Role.ADMIN)) {
-      userLinkBuilder.add("delete").method("getUserSubResource").parameters(target.getName()).method("delete").parameters();
-      userLinkBuilder.add("update").method("getUserSubResource").parameters(target.getName()).method("update").parameters();
-      collectionLinkBuilder.add("create").method("getUserCollectionResource").parameters().method("create").parameters();
+      links.put("delete", userLinkBuilder.method("getUserSubResource").parameters(target.getName()).method("delete").parameters().create());
+      links.put("update", userLinkBuilder.method("getUserSubResource").parameters(target.getName()).method("update").parameters().create());
+      links.put("create", collectionLinkBuilder.method("getUserCollectionResource").parameters().method("create").parameters().create());
     }
-    Map<String, Link> join = new HashMap<>();
-    join.putAll(userLinkBuilder.getLinkMap());
-    join.putAll(collectionLinkBuilder.getLinkMap());
-    target.setLinks(join);
+    target.setLinks(links);
   }
 }

scm-webapp/src/main/java/sonia/scm/api/rest/resources/UserCollectionResource.java

@@ -73,9 +73,8 @@ public class UserCollectionResource extends AbstractManagerResource<User, UserEx
     User user = dtoToUserMapper.userDtoToUser(userDto, "");
     manager.create(user);
 
-    LinkMapBuilder builder = new LinkMapBuilder(uriInfo, UserNewResource.class, UserSubResource.class);
-    builder.add("self").method("getUserSubResource").parameters(user.getName()).method("get").parameters();
-    return Response.created(builder.getLinkMap().get("self").getHref()).build();
+    LinkBuilder builder = new LinkBuilder(uriInfo, UserNewResource.class, UserSubResource.class);
+    return Response.created(builder.method("getUserSubResource").parameters(user.getName()).method("get").parameters().create().getHref()).build();
   }
 
   @Override

scm-webapp/src/test/java/sonia/scm/api/rest/resources/LinkBuilderTest.java

@@ -12,7 +12,7 @@ import static org.junit.Assert.assertEquals;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
-public class LinkMapBuilderTest {
+public class LinkBuilderTest {
 
   @Path("base")
   public static class Main {
@@ -41,52 +41,60 @@ public class LinkMapBuilderTest {
 
   @Test
   public void shouldBuildSimplePath() {
-    LinkMapBuilder builder = new LinkMapBuilder(uriInfo, Main.class);
-    builder
-      .add("link")
-      .method("sub")
-      .parameters("param_x");
+    LinkBuilder builder = new LinkBuilder(uriInfo, Main.class);
 
-    URI actual = builder.getLinkMap().get("link").getHref();
+    URI actual = builder
+      .method("sub")
+      .parameters("param_x")
+      .create()
+      .getHref();
     assertEquals("http://example.com/base/main/param_x", actual.toString());
   }
 
   @Test
   public void shouldBuildPathOverSubResources() {
-    LinkMapBuilder builder = new LinkMapBuilder(uriInfo, Main.class, Sub.class);
-    builder
-      .add("link")
+    LinkBuilder builder = new LinkBuilder(uriInfo, Main.class, Sub.class);
+
+    URI actual =     builder
       .method("sub")
       .parameters("param_x")
       .method("x")
-      .parameters("param_y", "param_z");
-
-    URI actual = builder.getLinkMap().get("link").getHref();
+      .parameters("param_y", "param_z")
+      .create()
+      .getHref();
     assertEquals("http://example.com/base/main/param_x/sub/param_y/param_z", actual.toString());
   }
 
   @Test
   public void shouldBuildPathWithoutParameters() {
-    LinkMapBuilder builder = new LinkMapBuilder(uriInfo, NoParam.class);
-    builder
-      .add("link")
-      .method("get")
-      .parameters();
+    LinkBuilder builder = new LinkBuilder(uriInfo, NoParam.class);
 
-    URI actual = builder.getLinkMap().get("link").getHref();
+    URI actual = builder
+      .method("get")
+      .parameters()
+      .create()
+      .getHref();
     assertEquals("http://example.com/base", actual.toString());
   }
 
   @Test(expected = IllegalStateException.class)
   public void shouldFailForTooManyMethods() {
-    LinkMapBuilder builder = new LinkMapBuilder(uriInfo, Main.class);
+    LinkBuilder builder = new LinkBuilder(uriInfo, Main.class);
     builder
-      .add("link")
       .method("sub")
       .parameters("param_x")
       .method("x");
   }
 
+  @Test(expected = IllegalStateException.class)
+  public void shouldFailForTooFewMethods() {
+    LinkBuilder builder = new LinkBuilder(uriInfo, Main.class, Sub.class);
+    builder
+      .method("sub")
+      .parameters("param_x")
+      .create();
+  }
+
   @Before
   public void setBaseUri() throws URISyntaxException {
     when(uriInfo.getBaseUri()).thenReturn(new URI("http://example.com/"));