1、处理大文本
1 package com.demo;
2
3 import java.io.File;
4 import java.io.FileNotFoundException;
5 import java.io.FileReader;
6 import java.io.FileWriter;
7 import java.io.IOException;
8 import java.io.Reader;
9 import java.sql.Connection;
10 import java.sql.PreparedStatement;
11 import java.sql.ResultSet;
12 import java.sql.SQLException;
13
14 import org.junit.Test;
15
16 import com.utils.DButils;
17
18 //jdbc存大文本数据
19
20 public class Demo1 {
21 @Test
22 public void insert() throws SQLException, FileNotFoundException{
23 Connection con = null;
24 PreparedStatement st = null;
25 ResultSet result = null;
26 try {
27 con = DButils.getConnection();
28 String sql = "insert into testclob(id,resume) values(?,?)";
29 st = con.prepareStatement(sql);
30 st.setString(1,"1");
31
32 File file = new File("src/1.txt");
33 FileReader reader = new FileReader(file);
34
35 //设置大文本的列
36 st.setCharacterStream(2, reader, file.length());
37 int num = st.executeUpdate();
38 if(num>0){
39 System.out.println("插入成功");
40 }
41 }finally{
42 DButils.release(con, st, result);
43 }
44 }
45
46 //读取大文本数据
47 @Test
48 public void read() throws SQLException, IOException{
49 Connection con = null;
50 PreparedStatement st = null;
51 ResultSet result = null;
52
53 try {
54 con = DButils.getConnection();
55 String sql = "select id,resume from testclob where id='1'";
56 st = con.prepareStatement(sql);
57 result = st.executeQuery();
58 if(result.next()){
59 //String resume = result.getString("resume");不能用String保存，占用内存过大
60 Reader reader = result.getCharacterStream("resume");
61 FileWriter writer = new FileWriter("c:\1.text");
62 try{
63 int len = 0;
64 char buffer[] = new char[1024];
65 while((len=reader.read(buffer))>0){
66 writer.write(buffer, 0, len);
67 }
68 }finally{
69 if(reader!=null){
70 reader.close();
71 }
72 writer.close();
73 }
74 }
75 }finally{
76 DButils.release(con, st, result);
77 }
78 }
79
80 }
2、处理二进制文件
1 package com.demo;
2
3 import java.io.File;
4 import java.io.FileInputStream;
5 import java.io.FileNotFoundException;
6 import java.io.FileOutputStream;
7 import java.io.IOException;
8 import java.io.InputStream;
9 import java.io.OutputStream;
10 import java.sql.Connection;
11 import java.sql.PreparedStatement;
12 import java.sql.ResultSet;
13 import java.sql.SQLException;
14
15 import org.junit.Test;
16
17 import com.utils.DButils;
18
19 //jdbc存取二进制文件
20 public class Demo2 {
21 @Test
22 public void insert() throws SQLException, FileNotFoundException{
23 Connection con = null;
24 PreparedStatement st = null;
25 ResultSet result = null;
26 try{
27 con = DButils.getConnection();
28 String sql = "insert into testblob(id,image) values(?,?)";
29 st = con.prepareStatement(sql);
30 st.setString(1, "1");
31 File file = new File("src/1.jpg");
32 FileInputStream in = new FileInputStream(file);
33 st.setBinaryStream(2, in, file.length());
34 st.executeUpdate();
35 }finally{
36 DButils.release(con, st, result);
37 }
38 }
39
40 @Test
41 public void read() throws SQLException, IOException{
42 Connection con = null;
43 PreparedStatement st = null;
44 ResultSet result = null;
45 try{
46 con = DButils.getConnection();
47 String sql = "select id,image from testblob where id='1'";
48 st = con.prepareStatement(sql);
49 result = st.executeQuery();
50 if(result.next()){
51 InputStream in = result.getBinaryStream("image");
52 OutputStream out = new FileOutputStream("c:\1.jpg");
53 try{
54 int len = 0;
55 byte[] buffer = new byte[1024];
56 while((len=in.read(buffer))>0){
57 out.write(buffer, 0, len);
58 }
59 }finally{
60 if(in!=null){
61 in.close();
62 }
63 if(out!=null){
64 out.close();
65 }
66 }
67 }
68 }finally{
69 DButils.release(con, st, result);
70 }
71 }
72 }