Java tutorial
/* * Copyright (C) 2007 The Android Open Source Project * * 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 android.content; import android.annotation.UnsupportedAppUsage; import android.os.Parcel; import android.os.Parcelable; import android.util.ArrayMap; import android.util.Log; import java.util.ArrayList; import java.util.HashMap; import java.util.Map; import java.util.Set; /** * This class is used to store a set of values that the {@link ContentResolver} * can process. */ public final class ContentValues implements Parcelable { public static final String TAG = "ContentValues"; /** * @hide * @deprecated kept around for lame people doing reflection */ @Deprecated @UnsupportedAppUsage private HashMap<String, Object> mValues; private final ArrayMap<String, Object> mMap; /** * Creates an empty set of values using the default initial size */ public ContentValues() { mMap = new ArrayMap<>(); } /** * Creates an empty set of values using the given initial size * * @param size the initial size of the set of values */ public ContentValues(int size) { mMap = new ArrayMap<>(size); } /** * Creates a set of values copied from the given set * * @param from the values to copy */ public ContentValues(ContentValues from) { mMap = new ArrayMap<>(from.mMap); } /** * @hide * @deprecated kept around for lame people doing reflection */ @Deprecated @UnsupportedAppUsage private ContentValues(HashMap<String, Object> from) { mMap = new ArrayMap<>(); mMap.putAll(from); } /** {@hide} */ private ContentValues(Parcel in) { mMap = new ArrayMap<>(in.readInt()); in.readArrayMap(mMap, null); } @Override public boolean equals(Object object) { if (!(object instanceof ContentValues)) { return false; } return mMap.equals(((ContentValues) object).mMap); } /** {@hide} */ public ArrayMap<String, Object> getValues() { return mMap; } @Override public int hashCode() { return mMap.hashCode(); } /** * Adds a value to the set. * * @param key the name of the value to put * @param value the data for the value to put */ public void put(String key, String value) { mMap.put(key, value); } /** * Adds all values from the passed in ContentValues. * * @param other the ContentValues from which to copy */ public void putAll(ContentValues other) { mMap.putAll(other.mMap); } /** * Adds a value to the set. * * @param key the name of the value to put * @param value the data for the value to put */ public void put(String key, Byte value) { mMap.put(key, value); } /** * Adds a value to the set. * * @param key the name of the value to put * @param value the data for the value to put */ public void put(String key, Short value) { mMap.put(key, value); } /** * Adds a value to the set. * * @param key the name of the value to put * @param value the data for the value to put */ public void put(String key, Integer value) { mMap.put(key, value); } /** * Adds a value to the set. * * @param key the name of the value to put * @param value the data for the value to put */ public void put(String key, Long value) { mMap.put(key, value); } /** * Adds a value to the set. * * @param key the name of the value to put * @param value the data for the value to put */ public void put(String key, Float value) { mMap.put(key, value); } /** * Adds a value to the set. * * @param key the name of the value to put * @param value the data for the value to put */ public void put(String key, Double value) { mMap.put(key, value); } /** * Adds a value to the set. * * @param key the name of the value to put * @param value the data for the value to put */ public void put(String key, Boolean value) { mMap.put(key, value); } /** * Adds a value to the set. * * @param key the name of the value to put * @param value the data for the value to put */ public void put(String key, byte[] value) { mMap.put(key, value); } /** * Adds a null value to the set. * * @param key the name of the value to make null */ public void putNull(String key) { mMap.put(key, null); } /** * Returns the number of values. * * @return the number of values */ public int size() { return mMap.size(); } /** * Indicates whether this collection is empty. * * @return true iff size == 0 * {@hide} * TODO: consider exposing this new method publicly */ public boolean isEmpty() { return mMap.isEmpty(); } /** * Remove a single value. * * @param key the name of the value to remove */ public void remove(String key) { mMap.remove(key); } /** * Removes all values. */ public void clear() { mMap.clear(); } /** * Returns true if this object has the named value. * * @param key the value to check for * @return {@code true} if the value is present, {@code false} otherwise */ public boolean containsKey(String key) { return mMap.containsKey(key); } /** * Gets a value. Valid value types are {@link String}, {@link Boolean}, * {@link Number}, and {@code byte[]} implementations. * * @param key the value to get * @return the data for the value, or {@code null} if the value is missing or if {@code null} * was previously added with the given {@code key} */ public Object get(String key) { return mMap.get(key); } /** * Gets a value and converts it to a String. * * @param key the value to get * @return the String for the value */ public String getAsString(String key) { Object value = mMap.get(key); return value != null ? value.toString() : null; } /** * Gets a value and converts it to a Long. * * @param key the value to get * @return the Long value, or {@code null} if the value is missing or cannot be converted */ public Long getAsLong(String key) { Object value = mMap.get(key); try { return value != null ? ((Number) value).longValue() : null; } catch (ClassCastException e) { if (value instanceof CharSequence) { try { return Long.valueOf(value.toString()); } catch (NumberFormatException e2) { Log.e(TAG, "Cannot parse Long value for " + value + " at key " + key); return null; } } else { Log.e(TAG, "Cannot cast value for " + key + " to a Long: " + value, e); return null; } } } /** * Gets a value and converts it to an Integer. * * @param key the value to get * @return the Integer value, or {@code null} if the value is missing or cannot be converted */ public Integer getAsInteger(String key) { Object value = mMap.get(key); try { return value != null ? ((Number) value).intValue() : null; } catch (ClassCastException e) { if (value instanceof CharSequence) { try { return Integer.valueOf(value.toString()); } catch (NumberFormatException e2) { Log.e(TAG, "Cannot parse Integer value for " + value + " at key " + key); return null; } } else { Log.e(TAG, "Cannot cast value for " + key + " to a Integer: " + value, e); return null; } } } /** * Gets a value and converts it to a Short. * * @param key the value to get * @return the Short value, or {@code null} if the value is missing or cannot be converted */ public Short getAsShort(String key) { Object value = mMap.get(key); try { return value != null ? ((Number) value).shortValue() : null; } catch (ClassCastException e) { if (value instanceof CharSequence) { try { return Short.valueOf(value.toString()); } catch (NumberFormatException e2) { Log.e(TAG, "Cannot parse Short value for " + value + " at key " + key); return null; } } else { Log.e(TAG, "Cannot cast value for " + key + " to a Short: " + value, e); return null; } } } /** * Gets a value and converts it to a Byte. * * @param key the value to get * @return the Byte value, or {@code null} if the value is missing or cannot be converted */ public Byte getAsByte(String key) { Object value = mMap.get(key); try { return value != null ? ((Number) value).byteValue() : null; } catch (ClassCastException e) { if (value instanceof CharSequence) { try { return Byte.valueOf(value.toString()); } catch (NumberFormatException e2) { Log.e(TAG, "Cannot parse Byte value for " + value + " at key " + key); return null; } } else { Log.e(TAG, "Cannot cast value for " + key + " to a Byte: " + value, e); return null; } } } /** * Gets a value and converts it to a Double. * * @param key the value to get * @return the Double value, or {@code null} if the value is missing or cannot be converted */ public Double getAsDouble(String key) { Object value = mMap.get(key); try { return value != null ? ((Number) value).doubleValue() : null; } catch (ClassCastException e) { if (value instanceof CharSequence) { try { return Double.valueOf(value.toString()); } catch (NumberFormatException e2) { Log.e(TAG, "Cannot parse Double value for " + value + " at key " + key); return null; } } else { Log.e(TAG, "Cannot cast value for " + key + " to a Double: " + value, e); return null; } } } /** * Gets a value and converts it to a Float. * * @param key the value to get * @return the Float value, or {@code null} if the value is missing or cannot be converted */ public Float getAsFloat(String key) { Object value = mMap.get(key); try { return value != null ? ((Number) value).floatValue() : null; } catch (ClassCastException e) { if (value instanceof CharSequence) { try { return Float.valueOf(value.toString()); } catch (NumberFormatException e2) { Log.e(TAG, "Cannot parse Float value for " + value + " at key " + key); return null; } } else { Log.e(TAG, "Cannot cast value for " + key + " to a Float: " + value, e); return null; } } } /** * Gets a value and converts it to a Boolean. * * @param key the value to get * @return the Boolean value, or {@code null} if the value is missing or cannot be converted */ public Boolean getAsBoolean(String key) { Object value = mMap.get(key); try { return (Boolean) value; } catch (ClassCastException e) { if (value instanceof CharSequence) { // Note that we also check against 1 here because SQLite's internal representation // for booleans is an integer with a value of 0 or 1. Without this check, boolean // values obtained via DatabaseUtils#cursorRowToContentValues will always return // false. return Boolean.valueOf(value.toString()) || "1".equals(value); } else if (value instanceof Number) { return ((Number) value).intValue() != 0; } else { Log.e(TAG, "Cannot cast value for " + key + " to a Boolean: " + value, e); return null; } } } /** * Gets a value that is a byte array. Note that this method will not convert * any other types to byte arrays. * * @param key the value to get * @return the {@code byte[]} value, or {@code null} is the value is missing or not a * {@code byte[]} */ public byte[] getAsByteArray(String key) { Object value = mMap.get(key); if (value instanceof byte[]) { return (byte[]) value; } else { return null; } } /** * Returns a set of all of the keys and values * * @return a set of all of the keys and values */ public Set<Map.Entry<String, Object>> valueSet() { return mMap.entrySet(); } /** * Returns a set of all of the keys * * @return a set of all of the keys */ public Set<String> keySet() { return mMap.keySet(); } public static final Parcelable.Creator<ContentValues> CREATOR = new Parcelable.Creator<ContentValues>() { @Override public ContentValues createFromParcel(Parcel in) { return new ContentValues(in); } @Override public ContentValues[] newArray(int size) { return new ContentValues[size]; } }; @Override public int describeContents() { return 0; } @Override public void writeToParcel(Parcel parcel, int flags) { parcel.writeInt(mMap.size()); parcel.writeArrayMap(mMap); } /** * Unsupported, here until we get proper bulk insert APIs. * {@hide} */ @Deprecated @UnsupportedAppUsage public void putStringArrayList(String key, ArrayList<String> value) { mMap.put(key, value); } /** * Unsupported, here until we get proper bulk insert APIs. * {@hide} */ @SuppressWarnings("unchecked") @Deprecated @UnsupportedAppUsage public ArrayList<String> getStringArrayList(String key) { return (ArrayList<String>) mMap.get(key); } /** * Returns a string containing a concise, human-readable description of this object. * @return a printable representation of this object. */ @Override public String toString() { StringBuilder sb = new StringBuilder(); for (String name : mMap.keySet()) { String value = getAsString(name); if (sb.length() > 0) sb.append(" "); sb.append(name + "=" + value); } return sb.toString(); } }