Android 序列化的两种方式

在Android中经常会在两个Activity之间传输数据，又很多种方法可以实现，比如写在文件中，用SharedPreferences等等都可以实现，现在来介绍的是使用序列化的方式来传输数据。Android序列化一共有两种方式，一种是实现Serializable接口，另一种就是实现Parcelable接口。

实现Serializable接口

实现Serializable非常简单，只需要实现这个接口就可以了，没有实现Parcelable接口那么复杂。

/**
 * 实现Serializable接口
 */
 public class Student implements Serializable {
    private String name;
    private String sex;
    public Student() {
    }
    public Student(String name, String sex) {
        this.name = name;
        this.sex = sex;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +                ", sex='" + sex + '\'' +                '}';  
                

实现Parcelable接口

实现Parcelable接口比实现Serializable复杂了很多，但效率更高，是Android推荐的序列化方式。

/**
 * 实现Parcelable
 */
 public class Teacher implements Parcelable {
    private String name;
    private String sex;
    @Override
    public int describeContents() {
        return 0;
    }
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(this.name);
        dest.writeString(this.sex);
    }
    public Teacher() {
    }
    public Teacher(String name, String sex) {
        this.name = name;
        this.sex = sex;
    }
    protected Teacher(Parcel in) {
        this.name = in.readString();
        this.sex = in.readString();
    }
    public static final Parcelable.Creator CREATOR = new Parcelable.Creator() {
        @Override
        public Teacher createFromParcel(Parcel source) {
            return new Teacher(source);
        }
        @Override
        public Teacher[] newArray(int size) {
            return new Teacher[size];
        }
    };
    @Override
    public String toString() {
        return "Teacher{" +
                "name='" + name + '\'' +                ", sex='" + sex + '\'' +                '}';  
                

看到实现Parcelable接口是不是瞬间就懵逼了，用AndroidStudio的的可以安装一个插件，可以自动的将实现Parcelable接口。来张效果图大家感受下。（插件的名字叫Android parcelable code generator）

具体应用

上面我们已经实现了这两个接口，那么怎么来使用用这个呢？接下来就来用个demo来演示下，Student实现 Serializable接口，Teacher实现Parcelable接口，将这两个类从MainActivity传输给SecondActivity并在SecondActivity中显示出来。

Student.java

/**
 * 实现Serializable接口
 */
 public class Student implements Serializable {
    private String name;
    private String sex;
    public Student() {
    }
    public Student(String name, String sex) {
        this.name = name;
        this.sex = sex;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +                ", sex='" + sex + '\'' +                '}';  
                

Teacher

/**
 * 实现Parcelable
 */
 public class Teacher implements Parcelable {
    private String name;
    private String sex;
    @Override
    public int describeContents() {
        return 0;
    }
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(this.name);
        dest.writeString(this.sex);
    }
    public Teacher() {
    }
    public Teacher(String name, String sex) {
        this.name = name;
        this.sex = sex;
    }
    protected Teacher(Parcel in) {
        this.name = in.readString();
        this.sex = in.readString();
    }
    public static final Parcelable.Creator CREATOR = new Parcelable.Creator() {
        @Override
        public Teacher createFromParcel(Parcel source) {
            return new Teacher(source);
        }
        @Override
        public Teacher[] newArray(int size) {
            return new Teacher[size];
        }
    };
    @Override
    public String toString() {
        return "Teacher{" +
                "name='" + name + '\'' +                ", sex='" + sex + '\'' +                '}';  
                

MainActivity.java

public class MainActivity extends AppCompatActivity {
    private Button mButton;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mButton = (Button) findViewById(R.id.button);
        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, SecondActivity.class);
                Bundle bundle = new Bundle();
                Teacher teacher = new Teacher("teacher", "man");
                bundle.putParcelable("teacher", teacher);
                Student student = new Student("student", "femal");
                bundle.putSerializable("student", student);
                intent.putExtras(bundle);
                startActivity(intent);
            }
        });
    }
    }

SecondActivity.java

public class SecondActivity extends AppCompatActivity {
    private TextView mTextView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);
        mTextView = (TextView) findViewById(R.id.textview);
        Intent intent = getIntent();
        mTextView.append(intent.getExtras().getSerializable("student").toString() + "\n");
        mTextView.append(intent.getExtras().getParcelable("teacher").toString());
    }
    }

运行结果

到这里Android序列化已经介绍完了。

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