JsonController.java

import java.io.IOException;
import java.util.List;

import org.apache.commons.io.IOUtils;
import org.slim3.controller.Navigation;
import org.slim3.controller.SimpleController;
import org.slim3.datastore.Datastore;

import com.shin1ogawa.meta.Slim3ModelMeta;
import com.shin1ogawa.model.Slim3Model;

public class JsonController extends SimpleController {

  @Override
  protected Navigation run() throws Exception {
    response.setContentType("application/json");
    response.setCharacterEncoding("utf-8");
    try {
      String id = request.getParameter("id");
      if (isPost()) {
        if (id != null && id.isEmpty() == false) {
          return doPut(id);
        }
        return doPost();
      } else if (isPut()) {
        if (id == null || id.isEmpty()) {
          response.setStatus(400);
          return null;
        }
        return doPut(id);
      } else if (isDelete()) {
        if (id == null || id.isEmpty()) {
          response.setStatus(400);
          return null;
        }
        return doDelete(id);
      } else {
        if (id == null || id.isEmpty()) {
          return doList();
        }
        return doGet(id);
      }
    } finally {
      response.flushBuffer();
    }
  }

  static final Slim3ModelMeta meta = Slim3ModelMeta.get();

  Navigation doList() throws IOException {
    List<Slim3Model> list = Datastore.query(meta).asList();
    StringBuilder b = new StringBuilder("entities: [");
    boolean first = true;
    for (Slim3Model model : list) {
      if (first == false) {
        b.append(',');
      } else {
        first = false;
      }
      b.append(meta.modelToJson(model));
    }
    b.append("]");
    response.getWriter().print(b);
    return null;
  }

  Navigation doGet(String id) throws IOException {
    Slim3Model model = Datastore.getOrNull(meta, Datastore.createKey(meta, id));
    if (model == null) {
      response.setStatus(404);
      return null;
    }
    response.getWriter().print(meta.modelToJson(model));
    return null;
  }

  Navigation doPut(String id) throws IOException {
    Slim3Model model = Datastore.getOrNull(meta, Datastore.createKey(meta, id));
    if (model == null) {
      response.setStatus(404);
      return null;
    }
    String json = IOUtils.toString(request.getInputStream());
    Slim3Model newModel = meta.jsonToModel(json);
    model.setProp1(newModel.getProp1());
    Datastore.put(model);
    response.getWriter().print(meta.modelToJson(model));
    return null;
  }

  Navigation doPost() throws IOException {
    String json = IOUtils.toString(request.getInputStream());
    Slim3Model model = meta.jsonToModel(json);
    Datastore.put(model);
    response.getWriter().print(meta.modelToJson(model));
    return null;
  }

  Navigation doDelete(String id) throws IOException {
    Slim3Model model = Datastore.getOrNull(meta, Datastore.createKey(meta, id));
    if (model == null) {
      response.setStatus(404);
      return null;
    }
    Datastore.delete(model.getKey());
    response.getWriter().print(meta.modelToJson(model));
    return null;
  }
}

JsonControllerTest.java

import static org.hamcrest.CoreMatchers.*;
import static org.junit.Assert.*;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;

import org.junit.Test;
import org.slim3.datastore.Datastore;
import org.slim3.tester.ControllerTestCase;

import com.shin1ogawa.meta.Slim3ModelMeta;
import com.shin1ogawa.model.Slim3Model;

public class JsonControllerTest extends ControllerTestCase {

  static final String PATH = "/json";

  static final Slim3ModelMeta meta = Slim3ModelMeta.get();

  @Test public void post() throws NullPointerException, IllegalArgumentException,
      IOException, ServletException {
    int beforeCount = tester.count(Slim3Model.class);
    String content = "{\"prop1\":\"hoge\"}";
    tester.request.setInputStream(new JsonInputStream(content.getBytes("utf-8")));
    tester.request.setMethod("POST");
    tester.start(PATH);

    assertThat(tester.getController(), is(instanceOf(JsonController.class)));
    assertThat(tester.response.getStatus(), is(200));
    assertThat(tester.response.getContentType(), is("application/json"));

    assertThat("postなので1件増える", tester.count(Slim3Model.class), is(beforeCount + 1));
    Slim3Model model = meta.jsonToModel(tester.response.getOutputAsString());
    assertThat(model.getProp1(), is("hoge"));
  }

  @Test public void put() throws NullPointerException, IllegalArgumentException,
      IOException, ServletException {
    int beforeCount = tester.count(Slim3Model.class);
    String content = "{\"prop1\":\"hoge\"}";
    tester.request.addParameter("id", "8");
    tester.request.setInputStream(new JsonInputStream(content.getBytes("utf-8")));
    tester.request.setMethod("PUT");
    tester.start(PATH);

    assertThat(tester.getController(), is(instanceOf(JsonController.class)));
    assertThat(tester.response.getStatus(), is(200));
    assertThat(tester.response.getContentType(), is("application/json"));

    assertThat("putでは増えない", tester.count(Slim3Model.class), is(beforeCount));
    Slim3Model model = meta.jsonToModel(tester.response.getOutputAsString());
    assertThat(model.getKey(), is(Datastore.createKey(meta, "8")));
    assertThat(model.getProp1(), is("hoge"));
  }

  @Test public void postWithId() throws NullPointerException,
      IllegalArgumentException, IOException, ServletException {
    int beforeCount = tester.count(Slim3Model.class);
    String content = "{\"prop1\":\"hoge\"}";
    tester.request.addParameter("id", "8");
    tester.request.setInputStream(new JsonInputStream(content.getBytes("utf-8")));
    tester.request.setMethod("POST");
    tester.start(PATH);

    assertThat(tester.getController(), is(instanceOf(JsonController.class)));
    assertThat(tester.response.getStatus(), is(200));
    assertThat(tester.response.getContentType(), is("application/json"));

    assertThat("id有りPostはPut操作となり、増えない", tester.count(Slim3Model.class), is(beforeCount));
    Slim3Model model = meta.jsonToModel(tester.response.getOutputAsString());
    assertThat(model.getKey(), is(Datastore.createKey(meta, "8")));
    assertThat(model.getProp1(), is("hoge"));
  }

  static class JsonInputStream extends ServletInputStream {
    ByteArrayInputStream in;

    JsonInputStream(byte[] content) {
      this.in = new ByteArrayInputStream(content);
    }

    @Override public int available() throws IOException {
      return in.available();
    }

    @Override public int read() throws IOException {
      return in.read();
    }

    @Override public int read(byte[] b, int off, int len) throws IOException {
      return in.read(b, off, len);
    }
  }

  @Override public void setUp() throws Exception {
    super.setUp();
    List<Slim3Model> entities = new ArrayList<Slim3Model>();
    for (int i = 0; i < 10; i++) {
      Slim3Model model = new Slim3Model();
      model.setKey(Datastore.createKey(Slim3Model.class, String.valueOf(i)));
      model.setProp1(String.valueOf(i));
      entities.add(model);
    }
    Datastore.put(entities);
  }
}