将byte[]写入类对象中，不能完全写入,该如何解决

将byte[]写入类对象中，不能完全写入
见了一个需要传输的类，如下

Java code

public class FileInfoRequest implements Serializable{     private String sessionID;     private byte[] fileContent;             public String getsessionID() {       return sessionID;       }             public void setsessionID(String sessionid) {       this.sessionID = sessionid;       }                        public byte[] getFileContent() {       return fileContent;       }             public void setFileContent(byte[] fileContent) {       this.fileContent = fileContent;       }            }

Java code

sentFile=new File(filePath);            FileInputStream fis=new FileInputStream(sentFile);                        byte[] b=new byte[64];            try {                fis=new FileInputStream(sentFile);            } catch (FileNotFoundException e) {                // TODO Auto-generated catch block                e.printStackTrace();            }            request.setsessionID(sessionid);            while(fis.read(b,0,b.length)!=-1){                request.setFileContent(b);            }                        system.out.println(request.getfileContent().length);

Java code

import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.io.Serializable;public class Test {    public static void main(String[] args) {    FileInfoRequest fileInfoRequest = new FileInfoRequest();    fileInfoRequest.setsessionID("testSessionId");    fileInfoRequest.setFileContent("testFileContent".getBytes());//创建测试对象，并初始化    writeObjectToFile(fileInfoRequest, "c:/test.txt");    fileInfoRequest = readObjectFromFile("c:/test.txt");    System.out.println(fileInfoRequest.getsessionID() + "  "        + new String(fileInfoRequest.getFileContent()));//读出对象，并输出    }    /////////////////////////////////////////////////////////////////////////////////////////////////////////    private static <T> void writeObjectToFile(T t, String fileName) {// 将一个对象 写入文件，对象是可序列化的    if (t == null)        return;// 对象不存在 默认不写    ObjectOutputStream oos = null;    try {        oos = new ObjectOutputStream(new FileOutputStream(fileName));        oos.writeObject(t);        oos.writeObject(null);// //写入结束标志方便读取（如果不写入，在读取的时候无法定位读取结束）；    } catch (Exception e) {    } finally {        try {        if (oos != null)            oos.close();        } catch (Exception e) {        }    }    }    private static <T> T readObjectFromFile(String fileName) {// 从文件中读出一个对象    ObjectInputStream ois = null;    try {        ois = new ObjectInputStream(new FileInputStream(fileName));        T t = (T) ois.readObject();        return t;    } catch (Exception e) {    } finally {        try {        if (ois != null)            ois.close();        } catch (Exception e) {        }    }    return null;    }   }class FileInfoRequest implements Serializable {    private String sessionID;    private byte[] fileContent;    public String getsessionID() {    return sessionID;    }    public void setsessionID(String sessionid) {    this.sessionID = sessionid;    }    public byte[] getFileContent() {    return fileContent;    }    public void setFileContent(byte[] fileContent) {    this.fileContent = fileContent;    }}