Question

java 中 blob转字符串?

java 中 blob转字符串?有无例子?
现在遇到的问题是:

BufferInputStream is=new BufferInputStream(blob.getBinaryStream())

byte [] by=new byte[大小?]
is.read(by);

现在想new1个byte类型,但大小似乎获取不到.
不知道有更好方法没有?

Answer 1

//字符串转blob
String str="哈哈哈哈哈哈";
java.sql.Blob bl=new SerialBlob(str.getBytes());
//blob转字符串
BufferedReader bf=new BufferedReader(new InputStreamReader(bl.getBinaryStream()));
String temp="";
StringBuffer sb=new StringBuffer();
while((temp=bf.readLine())!=null)
{
sb.append(temp);
}

System.out.println(sb.toString());

Answer 2

ByteArrayOutputStream cache = new ByteArrayOutputStream();
byte[] buf = new byte[512];
int c = -1;

while(( c = is.read(buf)) != -1) {
cache.write(buf, 0, c);
}

String result = new String(cache.toByteArray(), "你的字符集，可以不指定");

Answer 3

BufferedInputStream bi = new BufferedInputStream(blob.getBinaryStream());
data= new byte[READ_BUFFER_SIZE];
for (int len = 0; (len = bi.read(data)) != -1;) {
outfile+=new String(data,"GBK");
data= new byte[READ_BUFFER_SIZE];

}

在循环里面要清空data
因为read只是覆盖的读,而不是清空了读,所以要重新new bate[]

Answer 4

可以定义为数组，那个大小长度要一定，然后慢慢读取

Answer 5

ReadInputStream去读，读出来的就只字符串