Android Open Source - TipOnDiscount Preferences File Persister

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Back to project page TipOnDiscount.
License

The source code is released under:
GNU General Public License
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Java Source Code

package com.itllp.tipOnDiscount.persistence.impl;
// w w  w  .ja  v a2s .  co  m
import java.math.BigDecimal;

import android.content.Context;
import android.content.SharedPreferences;

import com.itllp.tipOnDiscount.persistence.Persister;

/* The preferences are stored in a SharedPreferences file. 
 * All instances of an app share the same instance of this file 
 */
public class PreferencesFilePersister implements Persister {

  private String preferencesFileName = null;
  private SharedPreferences.Editor editor = null;
  
  public PreferencesFilePersister(String preferencesFileName) {
    this.preferencesFileName = preferencesFileName;
  }
  
  @Override
  public void beginSave(Context context) {
    SharedPreferences prefs = context.getSharedPreferences(
        this.preferencesFileName, 
        android.content.Context.MODE_PRIVATE);
    editor = prefs.edit();
    editor.clear();
  }

  @Override
  public void save(String key, BigDecimal value) throws Exception {
    if (null == editor) {
      throw new Exception("beginSave must be called first");
    }
    if (null == key) {
      throw new Exception("key may not be null");
    }
    if (null == value) {
      throw new Exception("value may not be null");
    }
        String stringValue = value.toPlainString();
        editor.putString(key, stringValue);
  }

  @Override
  public void save(String key, boolean value) throws Exception {
    if (null == editor) {
      throw new Exception("beginSave must be called first");
    }
    if (null == key) {
      throw new Exception("key may not be null");
    }
        editor.putBoolean(key, value);
  }

  @Override
  public void save(String key, int value) throws Exception {
    if (null == editor) {
      throw new Exception("beginSave not called");
    }
    if (null == key) {
      throw new Exception("key may not be null");
    }
        editor.putInt(key, value);
  }

  @Override
  public void endSave() throws Exception {
    if (null == editor) {
      throw new Exception("beginSave must be called first");
    }
    editor.commit();
    editor = null;
  }

  @Override
  public BigDecimal retrieveBigDecimal(Context context, String key) {
    SharedPreferences prefs =
        context.getSharedPreferences(
            this.preferencesFileName, 
            android.content.Context.MODE_PRIVATE);
    if (!prefs.contains(key)) {
      return null;
    }
    String noValue = "";
        String stringValue = prefs.getString(key, noValue);
        BigDecimal bigDecimalValue = null;
        if (null != stringValue) {
          try {
            bigDecimalValue = new BigDecimal(stringValue);
          } catch (NumberFormatException x) {
            // leave bigDecimalValue == null
          }
        }
    return bigDecimalValue;
  }

  
  @Override
  public Boolean retrieveBoolean(Context context, String key) {
    SharedPreferences prefs =
        context.getSharedPreferences(
            this.preferencesFileName, 
            android.content.Context.MODE_PRIVATE);
    if (!prefs.contains(key)) {
      return null;
    }
    Boolean booleanValue = null;
        try {
          boolean boolValue = prefs.getBoolean(key, false);
          booleanValue = Boolean.valueOf(boolValue);
        } catch (Exception x) {
          // leave booleanValue == null
        }
    return booleanValue;
  }

  
  @Override
  public Integer retrieveInteger(Context context, String key) {
    SharedPreferences prefs =
        context.getSharedPreferences(
            this.preferencesFileName, 
            android.content.Context.MODE_PRIVATE);
    if (!prefs.contains(key)) {
      return null;
    }
    Integer integerValue = null;
        try {
          int intValue = prefs.getInt(key, Integer.MIN_VALUE);
          integerValue = Integer.valueOf(intValue);
        } catch (Exception x) {
          // leave integerValue == null
        }
    return integerValue;
  }

}
Java Source Code List
