Support JsonReader API on DOM objects.
This still needs test coverage & documentation but it appears to work!
This commit is contained in:
Jesse Wilson
parent
423d18feb5
commit
bd2a0ac466
@ -0,0 +1,192 @@
|
||||
/*
|
||||
* Copyright (C) 2011 Google Inc.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
|
||||
package com.google.gson.internal.bind;
|
||||
|
||||
import com.google.gson.JsonArray;
|
||||
import com.google.gson.JsonElement;
|
||||
import com.google.gson.JsonNull;
|
||||
import com.google.gson.JsonObject;
|
||||
import com.google.gson.JsonPrimitive;
|
||||
import com.google.gson.stream.JsonReader;
|
||||
import com.google.gson.stream.JsonToken;
|
||||
import java.io.IOException;
|
||||
import java.io.Reader;
|
||||
import java.util.ArrayList;
|
||||
import java.util.Iterator;
|
||||
import java.util.List;
|
||||
import java.util.Map;
|
||||
|
||||
/**
|
||||
*
|
||||
*/
|
||||
public final class JsonElementReader extends JsonReader {
|
||||
private static final Reader UNREADABLE_READER = new Reader() {
|
||||
@Override public int read(char[] buffer, int offset, int count) throws IOException {
|
||||
throw new AssertionError();
|
||||
}
|
||||
@Override public void close() throws IOException {
|
||||
throw new AssertionError();
|
||||
}
|
||||
};
|
||||
|
||||
private final List<Object> stack = new ArrayList<Object>();
|
||||
|
||||
/**
|
||||
* Creates a new instance that reads a JSON-encoded stream from {@code in}.
|
||||
*/
|
||||
public JsonElementReader(JsonElement element) {
|
||||
super(UNREADABLE_READER);
|
||||
stack.add(element);
|
||||
}
|
||||
|
||||
@Override public void beginArray() throws IOException {
|
||||
expect(JsonToken.BEGIN_ARRAY);
|
||||
JsonArray array = (JsonArray) peekStack();
|
||||
stack.add(array.iterator());
|
||||
}
|
||||
|
||||
@Override public void endArray() throws IOException {
|
||||
expect(JsonToken.END_ARRAY);
|
||||
popStack(); // empty iterator
|
||||
popStack(); // array
|
||||
}
|
||||
|
||||
@Override public void beginObject() throws IOException {
|
||||
expect(JsonToken.BEGIN_OBJECT);
|
||||
JsonObject object = (JsonObject) peekStack();
|
||||
stack.add(object.entrySet().iterator());
|
||||
}
|
||||
|
||||
@Override public void endObject() throws IOException {
|
||||
expect(JsonToken.END_OBJECT);
|
||||
popStack(); // empty iterator
|
||||
popStack(); // object
|
||||
}
|
||||
|
||||
@Override public boolean hasNext() throws IOException {
|
||||
JsonToken token = peek();
|
||||
return token != JsonToken.END_OBJECT && token != JsonToken.END_ARRAY;
|
||||
}
|
||||
|
||||
@Override public JsonToken peek() throws IOException {
|
||||
if (stack.isEmpty()) {
|
||||
return JsonToken.END_DOCUMENT;
|
||||
}
|
||||
|
||||
Object o = peekStack();
|
||||
if (o instanceof Iterator) {
|
||||
boolean isObject = stack.get(stack.size() - 2) instanceof JsonObject;
|
||||
Iterator<?> iterator = (Iterator<?>) o;
|
||||
if (iterator.hasNext()) {
|
||||
if (isObject) {
|
||||
return JsonToken.NAME;
|
||||
} else {
|
||||
stack.add(iterator.next());
|
||||
return peek();
|
||||
}
|
||||
} else {
|
||||
return isObject ? JsonToken.END_OBJECT : JsonToken.END_ARRAY;
|
||||
}
|
||||
} else if (o instanceof JsonObject) {
|
||||
return JsonToken.BEGIN_OBJECT;
|
||||
} else if (o instanceof JsonArray) {
|
||||
return JsonToken.BEGIN_ARRAY;
|
||||
} else if (o instanceof JsonPrimitive) {
|
||||
JsonPrimitive primitive = (JsonPrimitive) o;
|
||||
if (primitive.isString()) {
|
||||
return JsonToken.STRING;
|
||||
} else if (primitive.isBoolean()) {
|
||||
return JsonToken.BOOLEAN;
|
||||
} else if (primitive.isNumber()) {
|
||||
return JsonToken.NUMBER;
|
||||
} else {
|
||||
throw new AssertionError();
|
||||
}
|
||||
} else if (o instanceof JsonNull) {
|
||||
return JsonToken.NULL;
|
||||
} else {
|
||||
throw new AssertionError();
|
||||
}
|
||||
}
|
||||
|
||||
private Object peekStack() {
|
||||
return stack.get(stack.size() - 1);
|
||||
}
|
||||
|
||||
private Object popStack() {
|
||||
return stack.remove(stack.size() - 1);
|
||||
}
|
||||
|
||||
private void expect(JsonToken expected) throws IOException {
|
||||
if (peek() != expected) {
|
||||
throw new IllegalStateException("Expected " + expected + " but was " + peek());
|
||||
}
|
||||
}
|
||||
|
||||
@Override public String nextName() throws IOException {
|
||||
expect(JsonToken.NAME);
|
||||
Iterator<?> i = (Iterator) peekStack();
|
||||
Map.Entry<?, ?> entry = (Map.Entry<?, ?>) i.next();
|
||||
stack.add(entry.getValue());
|
||||
return (String) entry.getKey();
|
||||
}
|
||||
|
||||
@Override public String nextString() throws IOException {
|
||||
expect(JsonToken.STRING);
|
||||
return ((JsonPrimitive) popStack()).getAsString();
|
||||
}
|
||||
|
||||
@Override public boolean nextBoolean() throws IOException {
|
||||
expect(JsonToken.BOOLEAN);
|
||||
return ((JsonPrimitive) popStack()).getAsBoolean();
|
||||
}
|
||||
|
||||
@Override public void nextNull() throws IOException {
|
||||
expect(JsonToken.NULL);
|
||||
popStack();
|
||||
}
|
||||
|
||||
@Override public double nextDouble() throws IOException {
|
||||
expect(JsonToken.NUMBER);
|
||||
return ((JsonPrimitive) popStack()).getAsDouble();
|
||||
}
|
||||
|
||||
@Override public long nextLong() throws IOException {
|
||||
expect(JsonToken.NUMBER);
|
||||
return ((JsonPrimitive) popStack()).getAsLong();
|
||||
}
|
||||
|
||||
@Override public int nextInt() throws IOException {
|
||||
expect(JsonToken.NUMBER);
|
||||
return ((JsonPrimitive) popStack()).getAsInt();
|
||||
}
|
||||
|
||||
@Override public void close() throws IOException {
|
||||
}
|
||||
|
||||
@Override public void skipValue() throws IOException {
|
||||
if (peek() == JsonToken.NAME) {
|
||||
nextName();
|
||||
} else {
|
||||
popStack();
|
||||
}
|
||||
}
|
||||
|
||||
@Override public String toString() {
|
||||
return getClass().getSimpleName();
|
||||
}
|
||||
}
|
||||
@ -183,7 +183,7 @@ import java.util.List;
|
||||
* @author Jesse Wilson
|
||||
* @since 1.6
|
||||
*/
|
||||
public final class JsonReader implements Closeable {
|
||||
public class JsonReader implements Closeable {
|
||||
|
||||
/** The only non-execute prefix this parser permits */
|
||||
private static final char[] NON_EXECUTE_PREFIX = ")]}'\n".toCharArray();
|
||||
@ -279,14 +279,14 @@ public final class JsonReader implements Closeable {
|
||||
* <li>Name/value pairs separated by {@code ;} instead of {@code ,}.
|
||||
* </ul>
|
||||
*/
|
||||
public void setLenient(boolean lenient) {
|
||||
public final void setLenient(boolean lenient) {
|
||||
this.lenient = lenient;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns true if this parser is liberal in what it accepts.
|
||||
*/
|
||||
public boolean isLenient() {
|
||||
public final boolean isLenient() {
|
||||
return lenient;
|
||||
}
|
||||
|
||||
|
||||
@ -0,0 +1,76 @@
|
||||
/*
|
||||
* Copyright (C) 2011 Google Inc.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
|
||||
package com.google.gson.internal.bind;
|
||||
|
||||
import com.google.gson.JsonElement;
|
||||
import com.google.gson.JsonParser;
|
||||
import com.google.gson.stream.JsonToken;
|
||||
import java.io.IOException;
|
||||
import junit.framework.TestCase;
|
||||
|
||||
public final class JsonElementReaderTest extends TestCase {
|
||||
|
||||
public void testArray() throws IOException {
|
||||
JsonElement array = new JsonParser().parse("[1, 2, 3]");
|
||||
JsonElementReader reader = new JsonElementReader(array);
|
||||
assertEquals(JsonToken.BEGIN_ARRAY, reader.peek());
|
||||
reader.beginArray();
|
||||
assertEquals(JsonToken.NUMBER, reader.peek());
|
||||
assertEquals(1, reader.nextInt());
|
||||
assertEquals(JsonToken.NUMBER, reader.peek());
|
||||
assertEquals(2, reader.nextInt());
|
||||
assertEquals(JsonToken.NUMBER, reader.peek());
|
||||
assertEquals(3, reader.nextInt());
|
||||
assertEquals(JsonToken.END_ARRAY, reader.peek());
|
||||
reader.endArray();
|
||||
assertEquals(JsonToken.END_DOCUMENT, reader.peek());
|
||||
}
|
||||
|
||||
public void testObject() throws IOException {
|
||||
JsonElement array = new JsonParser().parse("{\"A\": 1, \"B\": 2}");
|
||||
JsonElementReader reader = new JsonElementReader(array);
|
||||
assertEquals(JsonToken.BEGIN_OBJECT, reader.peek());
|
||||
reader.beginObject();
|
||||
assertEquals(JsonToken.NAME, reader.peek());
|
||||
assertEquals("A", reader.nextName());
|
||||
assertEquals(JsonToken.NUMBER, reader.peek());
|
||||
assertEquals(1, reader.nextInt());
|
||||
assertEquals(JsonToken.NAME, reader.peek());
|
||||
assertEquals("B", reader.nextName());
|
||||
assertEquals(JsonToken.NUMBER, reader.peek());
|
||||
assertEquals(2, reader.nextInt());
|
||||
assertEquals(JsonToken.END_OBJECT, reader.peek());
|
||||
reader.endObject();
|
||||
assertEquals(JsonToken.END_DOCUMENT, reader.peek());
|
||||
}
|
||||
|
||||
public void testEmptyArray() throws IOException {
|
||||
JsonElement array = new JsonParser().parse("[]");
|
||||
JsonElementReader reader = new JsonElementReader(array);
|
||||
reader.beginArray();
|
||||
reader.endArray();
|
||||
}
|
||||
|
||||
public void testEmptyObject() throws IOException {
|
||||
JsonElement array = new JsonParser().parse("{}");
|
||||
JsonElementReader reader = new JsonElementReader(array);
|
||||
reader.beginObject();
|
||||
reader.endObject();
|
||||
}
|
||||
|
||||
// TODO: more test coverage
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user