java读取blob，clob转换为字符串

package com.it.test;import java.io.BufferedReader;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;import oracle.sql.BLOB;public class Test { /***
* 读取oracleCLOB字段内容
*
* @param conn
* @return
*/
public static String readCLOB(Connection conn) {
String sql = "select 大字段1,大字段2 from 印章基本信息_char_ccbb where yzbm='2'";
String content = "";
try {
conn.setAutoCommit(false);
PreparedStatement ps1 = conn.prepareStatement(sql);
ResultSet rs1 = ps1.executeQuery();
while (rs1.next()) {
oracle.sql.CLOB clob = (oracle.sql.CLOB) rs1.getClob("大字段1"); BufferedReader in = new BufferedReader(clob.getCharacterStream());
StringWriter out = new StringWriter();
int c;
while ((c = in.read()) != -1) {
out.write(c);
}
content = out.toString();
System.out.println(content);// 输出CLOB内容
}
} catch (Exception e) {
e.printStackTrace();
}
return content;
} /***
* 读取oracle的blob转换为字符串
*
* @param conn
* @return
*/
public static String ConvertBLOBtoString(Connection conn) {
String newStr = ""; // 返回字符串
long BlobLength; // BLOB字段长度
byte[] bytes; // BLOB临时存储字节数组
int i = 1; // 循环变量
Statement st = null;
try {
st = conn.createStatement();
ResultSet rs = st.executeQuery("select 大字段2 from 印章基本信息_char_ccbb where yzbm='2'");
while (rs.next()) {
BLOB blob = (BLOB) rs.getBlob("大字段2");
byte[] msgContent = blob.getBytes(); // BLOB转换为字节数组
BlobLength = blob.length(); // 获取BLOB长度
if (msgContent == null || BlobLength == 0) // 如果为空，返回空值
{
return "";
} else {
while (i < BlobLength) // 循环处理字符串转换，每次1024；Oracle字符串限制最大4k
{
bytes = blob.getBytes(i, 1024);
i = i + 1024;
newStr = newStr + new String(bytes, "gb2312");
}
}
}
System.out.println(newStr);
System.out.println(newStr.length()); } catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} finally {
if (st != null) {
try {
st.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
return newStr;
}
}