OAF数据库动态图片的实现

将图片写入数据库：

表字段类型为BLOB，在OAF中创建对应的Item，关联到相应VO属性,Item syle 设为MessageFileUpload

提交后就会自动保存到数据库中，使用PL/SQL Developer查看图片是否存储。

读取图片并在网页中显示：

流程：获取临时文件夹物理路径---从VO读取数据---使用IO流输出图片-修改Image Item的Source属性。

获取临时文件夹物理路径（CO代码）：

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//物理路径

String phyPath = pageContext.getTemporaryImageLocation();

//相对路径

String relPath = pageContext.getTemporaryImageSource();

/*以下两行注释用于生成唯一图片名，可视需要使用*/

//String imageName = pageContext.generateUniqueImageName("UserIcon.gif",

//OAWebBeanConstants.OA_TEMPORARY_IMAGE);

String imageName = "UserIcon"+user_id+".gif";

Serializable[] parameters = { user_id, phyPath, imageName };

am.invokeMethod("queryUser", parameters);

//物理路径

String phyPath = pageContext.getTemporaryImageLocation();

//相对路径

String relPath = pageContext.getTemporaryImageSource();

/*以下两行注释用于生成唯一图片名，可视需要使用*/

//String imageName = pageContext.generateUniqueImageName("UserIcon.gif",

//OAWebBeanConstants.OA_TEMPORARY_IMAGE);

String imageName = "UserIcon"+user_id+".gif";

Serializable[] parameters = { user_id, phyPath, imageName };

am.invokeMethod("queryUser", parameters);

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public void queryUser(String user_id, String phyPath,

String imageName) {

//此处调用了视图的查询方法

getUserVO1().initQuery(new Number(Integer.parseInt(user_id)));

OAViewObject vo = (OAViewObject)getUserVO1();

BlobDomain image = null;

if (vo.hasNext()) {

Row row = vo.next();

image = (BlobDomain)row.getAttribute("Icon");

if (image != null)

initImage(image, phyPath, imageName);

}

}

public void queryUser(String user_id, String phyPath,

String imageName) {

//此处调用了视图的查询方法

getUserVO1().initQuery(new Number(Integer.parseInt(user_id)));

OAViewObject vo = (OAViewObject)getUserVO1();

BlobDomain image = null;

if (vo.hasNext()) {

Row row = vo.next();

image = (BlobDomain)row.getAttribute("Icon");

if (image != null)

initImage(image, phyPath, imageName);

}

}

public void queryUser(String user_id, String phyPath,
String imageName) {
//此处调用了视图的查询方法
getUserVO1().initQuery(new Number(Integer.parseInt(user_id)));
OAViewObject vo = (OAViewObject)getUserVO1();
BlobDomain image = null;
if (vo.hasNext()) {
Row row = vo.next();
image = (BlobDomain)row.getAttribute("Icon");
if (image != null)
initImage(image, phyPath, imageName);
}
}
public void queryUser(String user_id, String phyPath,
String imageName) {
//此处调用了视图的查询方法
getUserVO1().initQuery(new Number(Integer.parseInt(user_id)));
OAViewObject vo = (OAViewObject)getUserVO1();
BlobDomain image = null;
if (vo.hasNext()) {
Row row = vo.next();
image = (BlobDomain)row.getAttribute("Icon");
if (image != null)
initImage(image, phyPath, imageName);
}
}

使用IO流输出图片（AM代码）：

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private void initImage(BlobDomain image, String phyPath,

String imageName) {

File directory = new File(phyPath);

if (!directory.exists())

directory.mkdirs();

File imageFile = new File(directory, imageName);

try {

fromInputToOutput(image.getBinaryStream(),

new FileOutputStream(imageFile));

} catch (Exception exception) {

exception.printStackTrace();

}

//DEBUG专用，看看路径对不对

System.out.println(imageFile.getAbsolutePath());

}

/*复制方法，图片大可以增大byte块*/

public void fromInputToOutput(InputStream inputstream,

OutputStream outputstream) throws IOException {

byte abyte0[] = new byte[255];

for (int i = 255; i == 255; ) {

i = inputstream.read(abyte0);

if (i < 0)

break;

outputstream.write(abyte0, 0, i);

}

outputstream.close();

inputstream.close();

}

private void initImage(BlobDomain image, String phyPath,

String imageName) {

File directory = new File(phyPath);

if (!directory.exists())

directory.mkdirs();

File imageFile = new File(directory, imageName);

try {

fromInputToOutput(image.getBinaryStream(),

new FileOutputStream(imageFile));

} catch (Exception exception) {

exception.printStackTrace();

}

//DEBUG专用，看看路径对不对

System.out.println(imageFile.getAbsolutePath());

}

/*复制方法，图片大可以增大byte块*/

public void fromInputToOutput(InputStream inputstream,

OutputStream outputstream) throws IOException {

byte abyte0[] = new byte[255];

for (int i = 255; i == 255; ) {

i = inputstream.read(abyte0);

if (i < 0)

break;

outputstream.write(abyte0, 0, i);

}

outputstream.close();

inputstream.close();

}

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OAImageBean image =

(OAImageBean)webBean.findIndexedChildRecursive("Icon");

if (image != null) {

image.setSource(relPath + imageName);}

OAImageBean image =

(OAImageBean)webBean.findIndexedChildRecursive("Icon");

if (image != null) {

image.setSource(relPath + imageName);}

OAImageBean image =
(OAImageBean)webBean.findIndexedChildRecursive("Icon");
if (image != null) {
image.setSource(relPath + imageName);}
OAImageBean image =
(OAImageBean)webBean.findIndexedChildRecursive("Icon");
if (image != null) {
image.setSource(relPath + imageName);}

注解:

1.如果不需要显示图片，而只是提供下载，那么使用MessageDownload会容易得多（无需手动输出）

2.Image Item也可以用代码创建。

3.由于OAF默认的图片文件夹是在OA_MEDIA下，如果使用视图的临时变量作为Image Item的 Image URL引用，图片地址会错误

4.将图片存储于数据库中管理不易，性能也不如直接保存图片URL的好

5.生成的图片不论原格式是JPG.PNG或是GIF，统一为GIF浏览器也可以显示出来

6.此代码没有做安全处理，包括上传文件大小和文件类型