github.com/keysonZZZ/kmg@v0.0.0-20151121023212-05317bfd7d39/kmgRpc/kmgRpcJava/java/src/com/google/gson/FieldAttributes.java (about)

     1  /*
     2   * Copyright (C) 2009 Google Inc.
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   * http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  package com.google.gson;
    18  
    19  import com.google.gson.internal.$Gson$Preconditions;
    20  import java.lang.annotation.Annotation;
    21  import java.lang.reflect.Field;
    22  import java.lang.reflect.Type;
    23  import java.util.Arrays;
    24  import java.util.Collection;
    25  
    26  /**
    27   * A data object that stores attributes of a field.
    28   *
    29   * <p>This class is immutable; therefore, it can be safely shared across threads.
    30   *
    31   * @author Inderjeet Singh
    32   * @author Joel Leitch
    33   *
    34   * @since 1.4
    35   */
    36  public final class FieldAttributes {
    37    private final Field field;
    38  
    39    /**
    40     * Constructs a Field Attributes object from the {@code f}.
    41     *
    42     * @param f the field to pull attributes from
    43     */
    44    public FieldAttributes(Field f) {
    45      $Gson$Preconditions.checkNotNull(f);
    46      this.field = f;
    47    }
    48  
    49    /**
    50     * @return the declaring class that contains this field
    51     */
    52    public Class<?> getDeclaringClass() {
    53      return field.getDeclaringClass();
    54    }
    55  
    56    /**
    57     * @return the name of the field
    58     */
    59    public String getName() {
    60      return field.getName();
    61    }
    62  
    63    /**
    64     * <p>For example, assume the following class definition:
    65     * <pre class="code">
    66     * public class Foo {
    67     *   private String bar;
    68     *   private List&lt;String&gt; red;
    69     * }
    70     *
    71     * Type listParmeterizedType = new TypeToken&lt;List&lt;String&gt;&gt;() {}.getType();
    72     * </pre>
    73     *
    74     * <p>This method would return {@code String.class} for the {@code bar} field and
    75     * {@code listParameterizedType} for the {@code red} field.
    76     *
    77     * @return the specific type declared for this field
    78     */
    79    public Type getDeclaredType() {
    80      return field.getGenericType();
    81    }
    82  
    83    /**
    84     * Returns the {@code Class} object that was declared for this field.
    85     *
    86     * <p>For example, assume the following class definition:
    87     * <pre class="code">
    88     * public class Foo {
    89     *   private String bar;
    90     *   private List&lt;String&gt; red;
    91     * }
    92     * </pre>
    93     *
    94     * <p>This method would return {@code String.class} for the {@code bar} field and
    95     * {@code List.class} for the {@code red} field.
    96     *
    97     * @return the specific class object that was declared for the field
    98     */
    99    public Class<?> getDeclaredClass() {
   100      return field.getType();
   101    }
   102  
   103    /**
   104     * Return the {@code T} annotation object from this field if it exist; otherwise returns
   105     * {@code null}.
   106     *
   107     * @param annotation the class of the annotation that will be retrieved
   108     * @return the annotation instance if it is bound to the field; otherwise {@code null}
   109     */
   110    public <T extends Annotation> T getAnnotation(Class<T> annotation) {
   111      return field.getAnnotation(annotation);
   112    }
   113  
   114    /**
   115     * Return the annotations that are present on this field.
   116     *
   117     * @return an array of all the annotations set on the field
   118     * @since 1.4
   119     */
   120    public Collection<Annotation> getAnnotations() {
   121      return Arrays.asList(field.getAnnotations());
   122    }
   123  
   124    /**
   125     * Returns {@code true} if the field is defined with the {@code modifier}.
   126     *
   127     * <p>This method is meant to be called as:
   128     * <pre class="code">
   129     * boolean hasPublicModifier = fieldAttribute.hasModifier(java.lang.reflect.Modifier.PUBLIC);
   130     * </pre>
   131     *
   132     * @see java.lang.reflect.Modifier
   133     */
   134    public boolean hasModifier(int modifier) {
   135      return (field.getModifiers() & modifier) != 0;
   136    }
   137  
   138    /**
   139     * This is exposed internally only for the removing synthetic fields from the JSON output.
   140     *
   141     * @return true if the field is synthetic; otherwise false
   142     * @throws IllegalAccessException
   143     * @throws IllegalArgumentException
   144     */
   145    Object get(Object instance) throws IllegalAccessException {
   146      return field.get(instance);
   147    }
   148  
   149    /**
   150     * This is exposed internally only for the removing synthetic fields from the JSON output.
   151     *
   152     * @return true if the field is synthetic; otherwise false
   153     */
   154    boolean isSynthetic() {
   155      return field.isSynthetic();
   156    }
   157  }