为什么释放资源后无法删除tif文件？

Question

我想看这个tiff的bbox，完成后我想删除这个tiff，好像有一个未关闭的流导致tiff没有被删除。

public static void main(String[] args) throws Exception {
        File file = new File("E:\test\1\昂多.tif");
        GeoTiffReader reader = new GeoTiffReader(file);
        GridCoverage2D read = reader.read(null);
        Envelope2D coverageEnvelope = read.getEnvelope2D();
        Rectangle2D bounds2D = coverageEnvelope.getBounds2D();
        double[] bbox = {
                bounds2D.getMinX(), bounds2D.getMinY(),
                bounds2D.getMaxX(), bounds2D.getMaxY()
        };
        for (double v : bbox) {
            System.out.println(v);
        }
        read.dispose(true);
        reader.dispose();
        FileUtils.forceDelete(file);
    }

代码运行结果


98.408460773
30.078745248
98.460743439
30.115231446
Exception in thread "main" java.io.IOException: Unable to delete file: E:\test\昂多.tif
    at org.apache.commons.io.FileUtils.forceDelete(FileUtils.java:2400)
    at cn.gisdata.core.publish.strategyImpl.Test.main(Test.java:37)

Process finished with exit code 1

GeoTools GridCoverage2D 处置（布尔力）api 文档

public boolean dispose(boolean force)
Provides a hint that a coverage will no longer be accessed from a reference in user space. This method disposes the image only if at least one of the following conditions is true (otherwise this method do nothing):
force is true, or
The underlying image has no sinks.
This safety check helps to prevent the disposal of an image that still used in a JAI operation chain. It doesn't prevent the disposal in every cases however. When unsure about whatever a coverage is still in use or not, it is safer to not invoke this method and rely on the garbage collector instead.

Overrides:
dispose in class AbstractCoverage
Parameters:
force - true for forcing an inconditionnal disposal, or false for performing a conservative disposal. The recommanded value is false.
Returns:
true if this method disposed at least some resources, or false if this method vetoed against the disposal.
Since:
2.4
See Also:
PlanarImage.dispose()

Answer 1

修改代码

public static void main(String[] args) throws Exception {
        File file = new File("E:\test\1\昂多.tif");
        GridCoverage2D read = null;
        GeoTiffReader reader = null;
        try (FileInputStream is = new FileInputStream(file)){
            reader = new GeoTiffReader(is);
            read = reader.read(null);
            Envelope2D coverageEnvelope = read.getEnvelope2D();
            Rectangle2D bounds2D = coverageEnvelope.getBounds2D();
            double[] bbox = {
                    bounds2D.getMinX(), bounds2D.getMinY(),
                    bounds2D.getMaxX(), bounds2D.getMaxY()
            };
            for (double v : bbox) {
                System.out.println(v);
            }
        }finally {
            read.dispose(true);
            reader.dispose();
            FileUtils.forceDelete(file);
        }

    }

代码运行结果

98.408460773
30.078745248
98.460743439
30.115231446

Process finished with exit code 0

GeoTiffReader构造方法接受inputStream，所以这个输入流由我控制关闭

if (this.source instanceof InputStream || this.source instanceof ImageInputStream) {
                this.closeMe = false;
            }

为什么释放资源后无法删除tif文件？

Why can't I delete the tif file after releasing the resources?

gis

geotools