Java.lang.outofMemoryError: Java Heap Space während Bytea Download ⇐ Java

[Anonymous]

Ich verwende diesen Code, um Bytea -Objekt von postgresql herunterzuladen: < /p>

Code: Select all

public void initFileDBData() throws SQLException, IOException
{
if (ds == null)
{
throw new SQLException("Can't get data source");
}
Connection conn = ds.getConnection();

if (conn == null)
{
throw new SQLException("Can't get database connection");
}

PreparedStatement ps = null;

try
{
conn.setAutoCommit(false);
ps = conn.prepareStatement("SELECT * FROM PROCEDURE_FILES WHERE ID = ?");

ps.setInt(1, id);
ResultSet rs = ps.executeQuery();
while (rs.next())
{
String file_name = rs.getString("FILE_NAME");
InputStream binaryStreasm = rs.getBinaryStream("FILE");
FacesContext fc = FacesContext.getCurrentInstance();
ExternalContext ec = fc.getExternalContext();

ec.responseReset();
ec.setResponseContentLength(binaryStreasm.available());
ec.setResponseHeader("Content-Disposition", "attachment; filename=\"" + file_name + "\"");

byte[] buf;

buf = new byte[binaryStreasm.available()];
int offset = 0;
int numRead = 0;
while ((offset < buf.length) && ((numRead = binaryStreasm.read(buf, offset, buf.length - offset)) >= 0))
{
offset += numRead;
}

HttpServletResponse response
= (HttpServletResponse) FacesContext.getCurrentInstance()
.getExternalContext().getResponse();

response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=" + file_name);
response.getOutputStream().write(buf);
response.getOutputStream().flush();
response.getOutputStream().close();
FacesContext.getCurrentInstance().responseComplete();
}

}
finally
{
if (ps != null)
{
ps.close();
}
conn.close();
}
}
< /code>

Aber wenn ich den Code herunterlade, erhalte ich java.lang.outofMemoryError: Java Heap Space in dieser Zeile: < /p>

 buf = new byte[binaryStreasm.available()];
< /code>

Kann ich den Code irgendwie optimieren, um weniger Speicher zu konsumieren?public void initFileDBData() throws SQLException, IOException
{
if (ds == null)
{
throw new SQLException("Can't get data source");
}
Connection conn = ds.getConnection();

if (conn == null)
{
throw new SQLException("Can't get database connection");
}

PreparedStatement ps = null;

try
{
conn.setAutoCommit(false);
ps = conn.prepareStatement("SELECT *, octet_length(FILE) as file_length FROM PROCEDURE_FILES WHERE ID = ?");

ps.setInt(1, id);
ResultSet rs = ps.executeQuery();
while (rs.next())
{
String file_name = rs.getString("FILE_NAME");
FacesContext fc = FacesContext.getCurrentInstance();
ExternalContext ec = fc.getExternalContext();

ec.responseReset();
ec.setResponseContentLength(rs.getInt("file_length"));
ec.setResponseHeader("Content-Disposition", "attachment;  filename=\"" + file_name + "\"");

HttpServletResponse response
= (HttpServletResponse) FacesContext.getCurrentInstance()
.getExternalContext().getResponse();

byte[] buffer = new byte[4096];

try (InputStream input = rs.getBinaryStream("FILE");
OutputStream output = response.getOutputStream())
{
int numRead = 0;

while ((numRead = input.read(buffer)) != -1)
{
output.write(buffer, 0, numRead);
}
}

response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=" + file_name);
response.getOutputStream().write(buffer);
response.getOutputStream().flush();
response.getOutputStream().close();
FacesContext.getCurrentInstance().responseComplete();
}
}
finally
{
if (ps != null)
{
ps.close();
}
conn.close();
}
}