Add org.sonar.core.util.ContextException

diff --git a/sonar-core/src/main/java/org/sonar/core/util/ContextException.java b/sonar-core/src/main/java/org/sonar/core/util/ContextException.java
new file mode 100644 (file)
index 0000000..4335166
--- /dev/null
+++ b/sonar-core/src/main/java/org/sonar/core/util/ContextException.java
@@ -0,0 +1,170 @@
+/*
+ * SonarQube, open source software quality management tool.
+ * Copyright (C) 2008-2014 SonarSource
+ * mailto:contact AT sonarsource DOT com
+ *
+ * SonarQube is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * SonarQube is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.core.util;
+
+import com.google.common.base.Joiner;
+import com.google.common.collect.LinkedListMultimap;
+import com.google.common.collect.ListMultimap;
+import java.util.Iterator;
+import java.util.List;
+import javax.annotation.CheckForNull;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import org.apache.commons.lang.StringUtils;
+
+/**
+ * A runtime exception that provides contextual information as a list of key-value
+ * pairs. This information is added to the message and stack trace.
+ * <p>
+ * Example:
+ * <pre>
+ *   try {
+ *
+ *   } catch (Exception e) {
+ *     throw ContextException.of("Unable to assign issue", e)
+ *       .addContext("projectUuid", "P1")
+ *       .addContext("issueUuid", "I1")
+ *       .addContext("login", "felix");
+ *   }
+ * </pre>
+ * </p>
+ * <p>
+ * Contexts of nested {@link ContextException}s are merged:
+ * <pre>
+ *   try {
+ *     throw ContextException.of("Something wrong").addContext("login", "josette");
+ *   } catch (Exception e) {
+ *     throw ContextException.of("Unable to assign issue", e)
+ *       .addContext("issueUuid", "I1")
+ *       .addContext("login", "felix");
+ *   }
+ * </pre>
+ * </p>
+ * <p>
+ * The generated message, usually written to a log with stack trace, looks like:
+ * <pre>
+ *   Unable to assign issue | issueUuid=I1 | login=[josette,felix]
+ * </pre>
+ * </p>
+ */
+public class ContextException extends RuntimeException {
+
+  private static final Joiner COMMA_JOINER = Joiner.on(',');
+
+  // LinkedListMultimap is used to keep order of keys and values
+  private final ListMultimap<String, Object> context = LinkedListMultimap.create();
+
+  private ContextException(Throwable t) {
+    super(t);
+  }
+
+  private ContextException(String message, Throwable t) {
+    super(message, t);
+  }
+
+  private ContextException(String message) {
+    super(message);
+  }
+
+  private ContextException addContext(ContextException e) {
+    this.context.putAll(e.context);
+    return this;
+  }
+
+  public ContextException addContext(String key, @Nullable Object value) {
+    context.put(key, value);
+    return this;
+  }
+
+  public ContextException clearContext(String key) {
+    context.removeAll(key);
+    return this;
+  }
+
+  public ContextException setContext(String key, @Nullable Object value) {
+    clearContext(key);
+    return addContext(key, value);
+  }
+
+  /**
+   * Returns the values associated with {@code key}, if any, else returns an
+   * empty list.
+   */
+  public List<Object> getContext(String key) {
+    return context.get(key);
+  }
+
+  public static ContextException of(Throwable t) {
+    if (t instanceof ContextException) {
+      return new ContextException(t.getCause()).addContext((ContextException) t);
+    }
+    return new ContextException(t);
+  }
+
+  public static ContextException of(String message, Throwable t) {
+    if (t instanceof ContextException) {
+      return new ContextException(message, t.getCause()).addContext((ContextException) t);
+    }
+    return new ContextException(message, t);
+  }
+
+  public static ContextException of(String message) {
+    return new ContextException(message);
+  }
+
+  @Override
+  @Nonnull
+  public String getMessage() {
+    return format(super.getMessage());
+  }
+
+  /**
+   * Provides the message explaining the exception without the contextual data.
+   */
+  @CheckForNull
+  public String getRawMessage() {
+    return super.getMessage();
+  }
+
+  private String format(@Nullable String baseMessage) {
+    StringBuilder sb = new StringBuilder();
+    Iterator<String> keyIt = context.keySet().iterator();
+    if (StringUtils.isNotBlank(baseMessage)) {
+      sb.append(baseMessage);
+      if (keyIt.hasNext()) {
+        sb.append(" | ");
+      }
+    }
+    while (keyIt.hasNext()) {
+      String key = keyIt.next();
+      sb.append(key).append("=");
+      List<Object> values = getContext(key);
+      if (values.size() > 1) {
+        sb.append("[").append(COMMA_JOINER.join(values)).append("]");
+      } else if (values.size() == 1) {
+        sb.append(values.get(0));
+      }
+      if (keyIt.hasNext()) {
+        sb.append(" | ");
+      }
+    }
+    return sb.toString();
+  }
+}

diff --git a/sonar-core/src/test/java/org/sonar/core/util/ContextExceptionTest.java b/sonar-core/src/test/java/org/sonar/core/util/ContextExceptionTest.java
new file mode 100644 (file)
index 0000000..00ec678
--- /dev/null
+++ b/sonar-core/src/test/java/org/sonar/core/util/ContextExceptionTest.java
@@ -0,0 +1,99 @@
+/*
+ * SonarQube, open source software quality management tool.
+ * Copyright (C) 2008-2014 SonarSource
+ * mailto:contact AT sonarsource DOT com
+ *
+ * SonarQube is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * SonarQube is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+package org.sonar.core.util;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ContextExceptionTest {
+
+  public static final String LABEL = "something wrong";
+
+  @Test
+  public void only_label() throws Exception {
+    ContextException e = ContextException.of(LABEL);
+    assertThat(e.getMessage()).isEqualTo(LABEL);
+    assertThat(e.getRawMessage()).isEqualTo(LABEL);
+    assertThat(e.getCause()).isNull();
+  }
+
+  @Test
+  public void only_cause() throws Exception {
+    Exception cause = new Exception("cause");
+    ContextException e = ContextException.of(cause);
+    assertThat(e.getMessage()).isEqualTo("java.lang.Exception: cause");
+    assertThat(e.getRawMessage()).isEqualTo("java.lang.Exception: cause");
+    assertThat(e.getCause()).isSameAs(cause);
+  }
+
+  @Test
+  public void cause_and_message() throws Exception {
+    Exception cause = new Exception("cause");
+    ContextException e = ContextException.of(LABEL, cause);
+    assertThat(e.getMessage()).isEqualTo(LABEL);
+    assertThat(e.getRawMessage()).isEqualTo(LABEL);
+    assertThat(e.getCause()).isSameAs(cause);
+  }
+
+  @Test
+  public void addContext() throws Exception {
+    ContextException e = ContextException.of(LABEL)
+      .addContext("K1", "V1")
+      .addContext("K2", "V2");
+    assertThat(e).hasMessage(LABEL + " | K1=V1 | K2=V2");
+  }
+
+  @Test
+  public void setContext() throws Exception {
+    ContextException e = ContextException.of(LABEL)
+      .addContext("K1", "V1")
+      .setContext("K1", "V2");
+    assertThat(e).hasMessage(LABEL + " | K1=V2");
+  }
+
+  @Test
+  public void multiple_context_values() throws Exception {
+    ContextException e = ContextException.of(LABEL)
+      .addContext("K1", "V1")
+      .addContext("K1", "V2");
+    assertThat(e).hasMessage(LABEL + " | K1=[V1,V2]");
+  }
+
+  @Test
+  public void merge_ContextException() throws Exception {
+    ContextException cause = ContextException.of("cause").addContext("K1", "V1");
+    ContextException e = ContextException.of(cause)
+      .addContext("K1", "V11")
+      .addContext("K2", "V2");
+    assertThat(e.getContext("K1")).containsExactly("V1", "V11");
+    assertThat(e.getContext("K2")).containsOnly("V2");
+    assertThat(e).hasMessage("K1=[V1,V11] | K2=V2");
+  }
+
+  @Test
+  public void merge_ContextException_with_new_message() throws Exception {
+    ContextException cause = ContextException.of("cause").addContext("K1", "V1");
+    ContextException e = ContextException.of(LABEL, cause).addContext("K2", "V2");
+    assertThat(e.getContext("K1")).containsOnly("V1");
+    assertThat(e.getContext("K2")).containsOnly("V2");
+    assertThat(e).hasMessage(LABEL + " | K1=V1 | K2=V2");
+  }
+}