标签:next toc cse 编译 tran 转换 get let 地方
不依赖驱动更新blob字段,场景如下:tomcat发布到weblogic上,使用weblogic的连接池,就抛错了,如下:
java.lang.ClassCastException: weblogic.jdbc.wrapper.Blob_oracle_sql_BLOB
开发代码如下:
oracle.sql.BLOB blob = (oracle.sql.BLOB) rs.getBlob("TRANSFERDATA");
BufferedOutputStream bos = new BufferedOutputStream(blob.getBinaryOutputStream());
bos.write(define.getBytes("GBK"));
后来查了一下,原因是通过weblogic连接池取出的连接取出的blob对象是weblogic封装过的OracleThinBlob,而不是oracle.sql.BLOB。然后又看了一下OracleThinBlob的方法与oracle.sql.BLOB类似,所以采用了下面的写法,避免异常:
Object obj = rs.getBlob("TRANSFERDATA");
Class clazz = obj.getClass();
Method method = clazz.getMethod("getBinaryOutputStream", new Class[]{});
OutputStream os = (OutputStream)method.invoke(obj, new Object[]{});
BufferedOutputStream bos = new BufferedOutputStream(os);
bos.write(define.getBytes("GBK"));
/**
* 此方法用于执行对大对象进行操作的sql语句
* 传入的参数:blob对象
*/
public boolean execUpdateBlobSQL(String sql, String tJSONObj){
PreparedStatement pstmt = null;
ResultSet rs = null;
//System.out.println("下面是预编译ExecSQL...");
System.out.println("预编译ExecSQL执行时间:"+new java.util.Date()+"; ExecSQL : " + sql);
if (!mflag){
con = DBConnPool.getConnection();
}
try{
con.setAutoCommit(false);//addbyefeng 关闭自动提交
pstmt = con.prepareStatement(StrTool.GBKToUnicode(sql));
//循环传入的参数数据 将数组内的参数 赋值给 预编译sql
rs = pstmt.executeQuery(sql);
while (rs.next())
{
//注:此处很重要。得到oracle.sql.BLOB对象后反射转换为BufferedOutputStream,目的是不依赖驱动
Object obj = rs.getBlob("TRANSFERDATA");
Class<? extends Object> clazz = obj.getClass();
Method method = clazz.getMethod("getBinaryOutputStream", new Class[]{});
OutputStream os = (OutputStream)method.invoke(obj, new Object[]{});
BufferedOutputStream outStream = new BufferedOutputStream(os);
outStream.write(tJSONObj.getBytes("GBK"), 0, tJSONObj.getBytes("GBK").length);
os.flush();
outStream.flush();
os.close();
outStream.close();
}
rs.close();
pstmt.close();
if (!mflag){
con.commit();
con.close();
}
}
catch (Exception e){
// @@错误处理
System.out.println("### Error ExeSQL at execUpdateSQL: " + sql);
CError.buildErr(this, e.toString(), mErrors);
try{
if (pstmt != null){
//由于描述的问题,导致执行的sql错误百出,因此pstmt的关闭需要特殊处理
try{
pstmt.close();
}
catch (SQLException ex){
ex.printStackTrace();
}
finally{
try{
System.out.println("Sql‘s bug is very big: " + sql);
pstmt.close();
}
catch (SQLException ex){}
}
}
if (!mflag){
con.rollback();
con.close();
}
}
catch (SQLException ex){
//在这个地方,有可能会没有关闭连接
ex.printStackTrace();
return false;
}
return false;
}finally{
try {
if (rs != null) {
rs.close();
}
if (pstmt!=null) {
pstmt.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
return true;
}
/**
* 此方法用于执行对大对象进行操作的sql语句
* 传入的参数:blob对象
*/
public boolean execSetBlobDataSQL(String sql, String tJSONObj, String tColumn){
PreparedStatement pstmt = null;
ResultSet rs = null;
//System.out.println("下面是预编译ExecSQL...");
System.out.println("预编译ExecSQL执行时间:"+new java.util.Date()+"; ExecSQL : " + sql);
if (!mflag){
con = DBConnPool.getConnection();
}
try{
con.setAutoCommit(false);//addbyefeng 关闭自动提交
pstmt = con.prepareStatement(StrTool.GBKToUnicode(sql));
//循环传入的参数数据 将数组内的参数 赋值给 预编译sql
rs = pstmt.executeQuery(sql);
while (rs.next())
{
//注:此处很重要。得到oracle.sql.BLOB对象后反射转换为BufferedOutputStream,目的是不依赖驱动
Object obj = rs.getBlob(tColumn);
Class<? extends Object> clazz = obj.getClass();
Method method = clazz.getMethod("getBinaryOutputStream", new Class[]{});
OutputStream os = (OutputStream)method.invoke(obj, new Object[]{});
BufferedOutputStream outStream = new BufferedOutputStream(os);
outStream.write(tJSONObj.getBytes("GBK"), 0, tJSONObj.getBytes("GBK").length);
os.flush();
outStream.flush();
os.close();
outStream.close();
}
rs.close();
pstmt.close();
if (!mflag){
con.commit();
con.close();
}
}
catch (Exception e){
// @@错误处理
System.out.println("### Error ExeSQL at execUpdateSQL: " + sql);
CError.buildErr(this, e.toString(), mErrors);
try{
if (pstmt != null){
//由于描述的问题,导致执行的sql错误百出,因此pstmt的关闭需要特殊处理
try{
pstmt.close();
}
catch (SQLException ex){
ex.printStackTrace();
}
finally{
try{
System.out.println("Sql‘s bug is very big: " + sql);
pstmt.close();
}
catch (SQLException ex){}
}
}
if (!mflag){
con.rollback();
con.close();
}
}
catch (SQLException ex){
//在这个地方,有可能会没有关闭连接
ex.printStackTrace();
return false;
}
return false;
}finally{
try {
if (rs != null) {
rs.close();
}
if (pstmt!=null) {
pstmt.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
return true;
}
标签:next toc cse 编译 tran 转换 get let 地方
原文地址:https://blog.51cto.com/zhaoanan/2409302