我在 excel 文件中有一些地方,每个点都有一个 lng 和 lat 坐标。
现在我尝试使用谷歌地图静态地图api为每个点创建一个静态地图。
我有两个组件,一个解析器和一个加载器。
Parser 用于读取 excel 文件,而 loaded 用于加载图块。
我让加载程序在单独的线程中运行。
public class Parser {
private static Parser instance;
private StaticMapLoader loader;
private Parser(StaticMapLoader loader) {
this.loader = loader;
}
public synchronized static Parser getInstance(StaticMapLoader loader) {
if (instance == null) {
instance = new Parser(loader);
}
return instance;
}
public void parse(String path) {
List<Branch> result = new ArrayList<Branch>();
InputStream inp;
try {
inp = new FileInputStream(path);
Workbook wb = WorkbookFactory.create(inp);
Sheet sheet = wb.getSheetAt(0);
int rows = sheet.getLastRowNum();
for(Row r : sheet.getRows){
loader.addTask(r.type,r.name,r.x,r.y);
}
} catch (InvalidFormatException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// Branch bc = new Branch("网点1", null, null);
return result;
}
}
装载机:
public class StaticMapLoader extends Thread {
private final static Logger log = Logger.getLogger(StaticMapLoader.class);
private List<Task> tasks = new ArrayList<Task>();
private String tilePath;
private boolean running = false;
public StaticMapLoader(String saveDir) {
this.tilePath = saveDir;
}
@Override
public void run() {
while (running) {
log.debug("run " + tasks.size());
if (tasks.size() > 0) {
Task t = tasks.get(0);
if (t != null && t.status == Status.waiting) {
tasks.remove(0);
t.status = Status.running;
downLoad(t);
}
}
}
}
private void downLoad(Task t) {
log.debug(String.format("load data for " + t.toString()));
//down tiles and save
t.status=Status.success;
}
public void addTask(String type, String name, double x, double y) {
log.debug(String.format("add task of :%s,%s", type, name));
tasks.add(new Task(type,name,x,y));
}
public void startRunning() {
running = true;
this.start();
}
public void stopRunning() {
running = false;
this.interrupt();
}
class Task {
Status status = Status.waiting;
String type, name;
double x,y;
Task(String type, String name, double x,double y) {
this.type = type;
this.name = name;
this.xian = xian;
this.x = x;
this.y = y;
}
}
enum Status {
waiting, running, fail, success
}
}
该过程相当简单,StaticMapLoader
具有ArrayList
. 在Parser
解析记录(位置)时,它将被扔到列表中。
加载器将迭代列表并下载数据。
但是我在这里遇到了一个奇怪的问题:
@Override
public void run() {
while (running) {
log.debug("run " + tasks.size());
if (tasks.size() > 0) {
Task t = tasks.get(0);
if (t != null && t.status == Status.waiting) {
tasks.remove(0);
t.status = Status.running;
downLoad(t);
}
}
}
}
上面的代码运行,我会得到这样的日志:
run 1
add task of ..
run 2
add task of ...
但是,如果我评论日志行,downLoad
将永远不会被调用,我会得到:
run 1
run 2
......
看来这可能是由 Thread 引起的,我错过了什么吗?
顺便说一句,上面的代码在HttpServlet
上下文中运行,我这样开始它们:
@Override
public void init() throws ServletException {
super.init();
try {
URL fileUrl = getServletContext().getResource(getInitParameter("xlsxFile"));
URL tilePath = getServletContext().getResource(getInitParameter("tilePath"));
StaticMapLoader loader = new StaticMapLoader(tilePath.getPath());
loader.startRunning();
Parser.getInstance(loader).parse(fileUrl.getPath());
} catch (MalformedURLException e) {
}
}