java - 在类中初始化以下实例的最佳方法是什么？

考虑下面的类，其中我覆盖了OutputStream

public class MyOutputStream extends java.io.OutputStream {
    public String clientId = null;
    public String fileId = null;
    public String filelocation = null;
    public DBClient clientobj = null;
    public OuputStream out = null;

    public MyOuputStream(String clientid, String fileid, String filelocation) {
        this.clientid = clientid;
        this.fileid = fileid;
        this.filelocation = filelocation;
    }

    public void write(byte[] bytes) throws IOException {
        out.write(bytes);
    }

    private DBClient getInstance(String clientid, String fileid) throws DBClientException {
        return this.clientobj = DBClient.getInstance(clientid, fileid);
    }

    private OutputStream getOuputStream(DFSClient clientobj) throws Exception {
        return this.out = clientobj.getOutputStream();
    }
}

  在上面的代码中，使用MyOuputStream编写的DBClient对象和OuputStream必须在写操作之前进行初始化


有人，请给我建议一个合适的设计模式来解决这个问题。

最佳答案

假设您希望MyOutputStream将所有输出转发到从OutputStream对象检索的DBClient，则要扩展FilterOutputStream，因此您可以免费获得所有委托实现。

要使用它，必须将OutputStream从DBClient赋予FilterOutputStream构造函数，因此需要以静态方法准备数据。

public class MyOutputStream extends FilterOutputStream {

    private String clientId;
    private String fileId;
    private String fileLocation;
    private DBClient clientobj;

    public static MyOutputStream create(String clientId, String fileId, String fileLocation) {
        DBClient clientobj = DBClient.getInstance(clientId, fileId);
        return new MyOutputStream(clientId, fileId, fileLocation, clientobj);
    }

    private MyOutputStream(String clientId, String fileId, String fileLocation, DBClient clientobj) {
        super(clientobj.getOutputStream());
        this.clientId = clientId;
        this.fileId = fileId;
        this.fileLocation = fileLocation;
        this.clientobj = clientobj;
    }

}

现在，您不用写new MyOuputStream(clientId, fileId, fileLocation)，而是写MyOuputStream.create(clientId, fileId, fileLocation)。

关于java - 在类中初始化以下实例的最佳方法是什么？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/38780732/