社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 8769阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* ~s -"u *>  
**SiteFileFetch.java mE"},ksg  
*/ ;Ff5ooL{  
package NetFox; e3}o3c_  
import java.io.*; G\/7V L  
import java.net.*; ,xuA%CF-S  
m 4V0e~]  
on)$y&lu  
public class SiteFileFetch extends Thread { BOWR}n!g  
`m=u2kxY  
9q>rUoK^  
SiteInfoBean siteInfoBean = null; //文件信息Bean :{M1]0 NH  
long[] nStartPos; //开始位置 |5#iPw_wMY  
long[] nEndPos; //结束位置 k/.a yLq  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 !R3ZyZcX  
long nFileLength; //文件长度 Y!fgc<]'&  
boolean bFirst = true; //是否第一次取文件 xL} ~R7  
boolean bStop = false; //停止标志 A&7~] BR\  
File tmpFile; //文件下载的临时信息 +hz S'z)n&  
DataOutputStream output; //输出到文件的输出流 %TS8 9/  
OQ*rxL cA  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) EbMG9  
public SiteFileFetch(SiteInfoBean bean) throws IOException Erq% Ck(  
{ *;Gnod<  
siteInfoBean = bean;  ];hK5  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); oz#;7 ?9  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); (#5TM1/A  
if(tmpFile.exists ()) m1,yf*U  
{ T;Zv^:]0  
bFirst = false;   ]n (:X  
read_nPos(); $}z%}v  
} pPnJf{  
else w5R?9"d@  
{ bZd)4  
nStartPos = new long[bean.getNSplitter()]; :%kJ9zW  
nEndPos = new long[bean.getNSplitter()]; &N\4/'wV  
} U!Eo*?LU$  
Fa^I 1fk  
OYayTKxN  
_0 $W;8X  
} Ry4`Q$=:  
P h/!a6y  
U[WR?J4~LX  
public void run() 3v@Y"I3;  
{ H*VZ&{\7  
//获得文件长度 >TB Rp,;r  
//分割文件 +Qo]'xKr  
//实例FileSplitterFetch Mi2l BEu,  
//启动FileSplitterFetch线程 uZkh.0yB  
//等待子线程返回 _MST8  
try{ PR;A 0   
if(bFirst) )]P%=  
{ Z Vj  
nFileLength = getFileSize(); BIeeu@p  
if(nFileLength == -1) (5R_q.Wu  
{ ?0VETa ~m  
System.err.println("File Length is not known!"); ~$:=hT1  
} :iVEm9pB)  
else if(nFileLength == -2) R4q)FXW29  
{ rIo)'L$uU  
System.err.println("File is not access!"); ED=P  6u  
} -9@/S$i  
else Mr u  
{ 8>l#F<@5  
for(int i=0;i<nStartPos.length;i++) jO+#$=C  
{ wTK>U`o  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); { ((|IvP`  
} t?6_^ 08  
for(int i=0;i<nEndPos.length-1;i++) a?5R ;I B  
{ }`*DMI;-  
nEndPos = nStartPos[i+1]; ("5Eed  
} z3 Ro*yJU  
nEndPos[nEndPos.length-1] = nFileLength; [ r;hF  
} J sc`^a%`'  
} -]e@FNL  
'>0rp\jC  
>+ E  
//启动子线程 c</u]TD  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SJ;Kjq.Qo  
for(int i=0;i<nStartPos.length;i++) ;JAb8dyS2  
{ })^%>yLfc|  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |6y(7Ha  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :rhh=nHgn  
nStartPos,nEndPos,i); g_2EH  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `ot <BwxJ  
fileSplitterFetch.start(); P K9BowlW  
} ~n )<L7  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t,>j{SK~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'awZ-$#  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |JRaskd  
nEndPos = " + nFileLength); <$ oI  
// fileSplitterFetch[nPos.length-1].start(); ( V^C7ix:  
b am*&E%0K  
Z9vJF.clO  
//等待子线程结束 [S#QGB19  
//int count = 0; >UDb:N[  
//是否结束while循环 Wi3St`$  
boolean breakWhile = false; +(qs{07A$  
+PGtO9}B  
UYW{A G2C  
while(!bStop) , s .{R  
{ Weu%&u-  
write_nPos(); P@pJ^5Jf  
Utility.sleep(500); cW*p}hD  
breakWhile = true; DgB]y6~KXl  
q/l@J3p[qm  
R}VEq gq  
for(int i=0;i<nStartPos.length;i++) wjnQK  
{ LYvjqNC&4  
if(!fileSplitterFetch.bDownOver) !3 j@gi2  
{ pXBlTZf  
breakWhile = false; Z{gJm9  
break; 7m +d;x2  
} 4kqgZtg.  
} %L;;W,l$`)  
if(breakWhile) U{%N.4:   
break; wdzZ41y1  
Y]-7T-*+t  
-D-]tL6w  
//count++; UxS@]YC  
//if(count>4) 5^+QTQ  
// siteStop(); (iO8[  
} 9u2Mra  
c[RkiV3  
_(.,<R5  
System.err.println("文件下载结束!"); uxsfQ%3`#  
} C. rLog#  
catch(Exception e){e.printStackTrace ();} VvJ]*D+e  
} *4oj' }  
tH\ aHU[  
;4] sP^+  
//获得文件长度 k~+(X|!5w  
public long getFileSize() nL]-]n;  
{ <~}# Q,9  
int nFileLength = -1; nm.~~h+8M  
try{ h..D1(M  
URL url = new URL(siteInfoBean.getSSiteURL()); @ %}4R`S0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1deNrmp%  
httpConnection.setRequestProperty("User-Agent","NetFox"); ?}D|]i34  
1y)|m63&  
%e,X7W`'2  
int responseCode=httpConnection.getResponseCode(); VM[U&g<8n  
if(responseCode>=400) Dd:;8Xo  
{ SC 6cFyp2  
processErrorCode(responseCode); FsdxLMwk1  
return -2; //-2 represent access is error *'&mcEpg  
} u(92y]3,  
`+>'18F  
S_EN,2'e  
String sHeader; Nt^9N #+N  
Y Cbt(nmr  
B}y`E <  
for(int i=1;;i++) !J@!P?0. C  
{ /18VQ  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); P pF"n[j  
//Utility.log(in.readLine()); (g>>   
sHeader=httpConnection.getHeaderFieldKey(i); +>,4d  
if(sHeader!=null) _ Uxt9 X  
{ bw\a\/Dw  
if(sHeader.equals("Content-Length")) eJv_`#R&Of  
{ Q\ AM] U  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D3BNA]P\2@  
break; =5QP'Qt{O  
} 6JYVC>i  
} w?LDaSz\t  
else Np?%pB!Q  
break; N-g=_86C"  
} [LHx9(,NM  
} A^9RGz4=  
catch(IOException e){e.printStackTrace ();} hQT  p&  
catch(Exception e){e.printStackTrace ();} hb_J. Q  
?k7z 5ow  
?9)-?tZ^Q  
Utility.log(nFileLength); zYW+Goz/C  
r6#It$NU  
6AW{qU6  
return nFileLength; Eoo[)V#x{  
} ee0)%hc1t  
vg6 ' ^5S7  
jZX2)#a!  
//保存下载信息(文件指针位置) @TTB$  
private void write_nPos() }%;o#!<N(@  
{ V&75n.L  
try{ j~)GZV  
output = new DataOutputStream(new FileOutputStream(tmpFile)); .*bu:FuDE  
output.writeInt(nStartPos.length); MI,b`pQ  
for(int i=0;i<nStartPos.length;i++) Q{~WWv  
{ vA r fsgk  
// output.writeLong(nPos); =d{B.BP(  
output.writeLong(fileSplitterFetch.nStartPos); 9 Z 5!3  
output.writeLong(fileSplitterFetch.nEndPos); !Xzne_V<  
} JQt Bt2  
output.close(); DnZkZ;E/  
} s$,gM,|cK  
catch(IOException e){e.printStackTrace ();} #J,?oe=<4  
catch(Exception e){e.printStackTrace ();} N5SePA\ ,?  
} *C*'J7  
jM'kY|<g;  
uV@#;c4  
//读取保存的下载信息(文件指针位置) R zOs,  
private void read_nPos() S-$N!G~!  
{ :E>" z6H  
try{ \:To>A32  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v9<'nU WVR  
int nCount = input.readInt(); 0E5"}8  
nStartPos = new long[nCount]; *88Q6=Mm  
nEndPos = new long[nCount]; E W {vF|  
for(int i=0;i<nStartPos.length;i++) :=iP_*#  
{ 8?> #  
nStartPos = input.readLong(); %rmn+L),;  
nEndPos = input.readLong(); jOYa}jm?  
} l. 9 i `  
input.close(); *" ("^_x\  
} *K<|E15 ,  
catch(IOException e){e.printStackTrace ();} ODbEL/  
catch(Exception e){e.printStackTrace ();} m=hlim;P,  
} v|WTm#  
[T(XwA)  
gtV^6(Y  
private void processErrorCode(int nErrorCode) ?51Y&gOEZ  
{ !6R;fD#^s  
System.err.println("Error Code : " + nErrorCode); "zn<\z$l  
} * 7<{Xbsj^  
0I`)<o-  
/oWn0  
//停止文件下载 .}wVM`81z  
public void siteStop() q, 8TOn  
{ oV(|51(f  
bStop = true; X4c|*U=4  
for(int i=0;i<nStartPos.length;i++) EU@ BNja  
fileSplitterFetch.splitterStop(); RWe$ZZSz!  
Q||v U  
N5yt'.d  
} _\d[`7#  
} )tq&l>0h  
//负责部分文件的抓取 _XO3ml\x@  
**FileSplitterFetch.java ZCT\4Llv#  
*/ G`_LD+  
package NetFox; zmw <y2`  
)\q A[rTG  
C V{kP8#  
import java.io.*; . paA0j  
import java.net.*; 1kd\Fq^z$  
","O8'$OC  
:?2@qWaL  
public class FileSplitterFetch extends Thread { Cj,Yy  
d'oh-dj %^  
p-6Y5$Y  
String sURL; //File URL pdz_qj!Z  
long nStartPos; //File Snippet Start Position d3m!34ml  
long nEndPos; //File Snippet End Position '@ $L}C#OI  
int nThreadID; //Thread's ID o*[n[\cR  
boolean bDownOver = false; //Downing is over kK0.j)(  
boolean bStop = false; //Stop identical Q|DVB  
FileAccessI fileAccessI = null; //File Access interface Ap :mc:  
wb#ZRmx}  
e2~$=f-  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bvxol\7;  
{ @d+NeS  
this.sURL = sURL; X6hp}  
this.nStartPos = nStart; Skb d'j  
this.nEndPos = nEnd; Ke*tLnO  
nThreadID = id; 6D=9J%;  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u%o]r9xl'  
} u n)YK  
3>~W_c9@  
Y#/mE!&  
public void run() Rz #&v  
{ ~yGD("X  
while(nStartPos < nEndPos && !bStop) #cnh ~O  
{ ($h`Y;4  
uPmK:9]3R  
[1LlzCAFBw  
try{ (R9{wGV [  
URL url = new URL(sURL); Y-&SZI4H  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u/I|<NAC,  
httpConnection.setRequestProperty("User-Agent","NetFox"); XY_zF F  
String sProperty = "bytes="+nStartPos+"-"; nQtp4  
httpConnection.setRequestProperty("RANGE",sProperty); ?g6xy[  
Utility.log(sProperty); JB <GV-l  
wm'a)B?  
'o!{YLJ fM  
InputStream input = httpConnection.getInputStream(); _x2i=SFo*$  
//logResponseHead(httpConnection); -J06H&/k  
X0}+X'3  
6dN W2_  
byte[] b = new byte[1024]; 6H#4iMeh  
int nRead; C'wRF90  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Sb/`a~q ^  
{ xa=Lu?t%<  
nStartPos += fileAccessI.write(b,0,nRead); a7? )x])e  
//if(nThreadID == 1) x @a3STKT  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]SO-NR  
} MyJ\/`8  
Z]QpH<Z  
'&;s32']}  
Utility.log("Thread " + nThreadID + " is over!"); oy _DYop  
bDownOver = true; <27:O,I  
//nPos = fileAccessI.write (b,0,nRead); .:b&$~<  
}  Fhk 8  
catch(Exception e){e.printStackTrace ();} >iKbn  
}  jO5,PTV  
} OxC8xB;`  
<\fB+ AZ  
Jn#05Z  
//打印回应的头信息 Z)7|m  
public void logResponseHead(HttpURLConnection con) <Wwcd8d  
{ 4#D<#!]^  
for(int i=1;;i++) 7~I*u6zY  
{ t/kMV6  
String header=con.getHeaderFieldKey(i); w<P$)~6  
if(header!=null) wAvnj  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *6` };ASK  
Utility.log(header+" : "+con.getHeaderField(header)); Fmd^9K  
else !1b4q/  
break; 5fT"`FL?  
} auai@)v6  
} ;usR=i36b  
`q$a p$?  
j1141md 5  
public void splitterStop() :f/T $fa*  
{ |c)hyw?[Y  
bStop = true; :,@\q0j"=  
} TOx >Z  
}<9IH%sgF  
WSKubn?7B  
} @CUYl*.PD  
e|e"lP  
kR !O-@GJ]  
/* 6/=0RTd  
**FileAccess.java b)(rlX  
*//文件访问(定位,写) d$gT,+|vu  
package NetFox; # GbfFoE  
import java.io.*; }|j \QjH  
_-R&A@  
? koIZ  
public class FileAccessI implements Serializable{ ~x-v%x6  
 T1\@4x  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O!U8"Yr$  
RandomAccessFile oSavedFile; `:Bm@eN  
long nPos; 7/969h^s  
us7t>EMmB  
IyPk3N  
public FileAccessI() throws IOException !j8 DCVb  
{ LZI[5tA"  
this("",0); `Q!#v{  
} Oj,v88=  
Q&@e,7]V+  
iRIO~XVo  
public FileAccessI(String sName,long nPos) throws IOException )7jJ3G*  
{ xCYK"v6\  
oSavedFile = new RandomAccessFile(sName,"rw"); 4c'F.0^  
this.nPos = nPos; _wp_y-"  
oSavedFile.seek(nPos); \5pBK  
} WZQ EBXs  
6g-Q  
>At* jg48  
public synchronized int write(byte[] b,int nStart,int nLen) @d1YN]ede  
{ 3Jh!YzI8  
int n = -1; l8~s#:v6X  
try{ %E k!3t  
oSavedFile.write(b,nStart,nLen); hqW),^\>'  
n = nLen; (Zz8 ldO  
} dQQ!QbI(.  
catch(IOException e) 6BdK)s  
{ ) -^(Su(!  
e.printStackTrace (); @j`gx M_-O  
} 53<.Knw5a  
p&$O}AX|  
/_[?i"GW  
return n; /iw$\F |8  
} 35KRJY#  
hCPyCq]  
#;])/8R%  
} NyR,@n1  
H{et2J<H  
B(1WI_}~  
/* cfC}"As  
**SiteInfoBean.java V)Sw\tS6g  
*/ 7SJbrOL4Q-  
package NetFox; ^5n#hSqZ=M  
PSHzB! H=n  
<f9a%`d  
public class SiteInfoBean { [C`LKA$t  
<]f{X<ef  
X#<+D1P  
private String sSiteURL; //Site's URL !!+LFe4su  
private String sFilePath; //Saved File's Path ;wa#m1  
private String sFileName; //Saved File's Name VD~ %6AjyN  
private int nSplitter; //Count of Splited Downloading File "8iIOeY-\  
GCj[ySCD  
Gq]/6igzX  
public SiteInfoBean() :ggXVwpe  
{//nSplitter的缺省值为5 .(%]RSBY  
//default value of nSplitter is 5 | r,{#EE  
this("","","",5); D%*Ryg  
} -A^o5s  
jRN>^Ur;g  
f=IF_|@^S  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ):]5WHYg  
{ vyvb-oz;u  
sSiteURL= sURL; L]* 5cH  
sFilePath = sPath; G$[Hm\V  
sFileName = sName; gx.\&W b  
this.nSplitter = nSpiltter; Yq>K1E|  
lFN|)(X  
Y~k,AJ{ ^  
} %z6_,|%  
mEg3.|  
O>eg_K,c  
public String getSSiteURL() kD me>E=  
{ AD~_n ^  
return sSiteURL; B8~bx%)3T  
} F<4>g+Ag  
D]twid~OS  
K]&i9`>N   
public void setSSiteURL(String value) }Ud'j'QMy  
{ Ce/D[%  
sSiteURL = value; /V }Z,'+  
} FA{'Ki`  
meYGIP:n  
v, !`A!{D  
public String getSFilePath() ~NTKWRaR  
{ Zg9VkL6Z6  
return sFilePath; CT/>x3o  
} fRjp(m  
AO,^v+ $  
vty:@?3\  
public void setSFilePath(String value) .cz7jD  
{ wUfm)Q#  
sFilePath = value; `$MO;Fv,G  
} uT>"(wnJ|  
jN!VrRA  
j dkqJ4&i  
public String getSFileName() %6la@i  
{ u s8.nL/  
return sFileName; \olY)b[  
} Z>[n~{-,p  
0|kH0c,T-  
8p#V4liE  
public void setSFileName(String value) E.,  
{ BP@V:z  
sFileName = value; 0jt@|3  
} dKY#Tl]  
?e\u_3- 9  
PPde!}T$  
public int getNSplitter() iD<}r?Z  
{ %@8#+#@J0  
return nSplitter; C@g/{?\  
} q| UO]V  
]*D~>q"#\  
3G'cDemc  
public void setNSplitter(int nCount) ^iWJqpLe  
{ g"N&*V2  
nSplitter = nCount; P?@o?  
} p) ?6~\F:  
}  `7oYXk  
/m4Y87  
l{Et:W%|  
/* 8Vy/n^3)  
**Utility.java 1.5R`vKn]  
*/ b#*"eZj  
package NetFox; ,ZVhL* "  
>`<qa!9  
o7^0Lo5Z?  
public class Utility { </b_Rar  
%pLqX61t=  
S263h(H  
public Utility() Gr'|nR8  
{ NZ?dJ"eq7  
UgD)O:xaU  
8@ f+?g*i  
} jhkX U+4  
tF\_AvL_8  
//线程睡眠 ANfy+@  
public static void sleep(int nSecond) iu$Y0.H@  
{ _YN C}PUU  
try{ g9Ty%|Q7(  
Thread.sleep(nSecond); c< sq0('`  
} 8T8]gM  
catch(Exception e) PAH#yM2Ic  
{  yyGn <  
e.printStackTrace (); Gz4LjMQ &  
} 7eW6$$ju,N  
} C}ASVywc,1  
nW`] =  
//日志 ^V7)V)Z;0  
public static void log(String sMsg) |pBvy1e4)  
{ t^2$ent  
System.err.println(sMsg); :(4q\~  
} )@<HG$#  
|{RCvm  
9v1Snr  
public static void log(int sMsg) {;O j  
{ 9m<%+ S5&  
System.err.println(sMsg); U;*O7K=P  
} ce*?crOV  
} Kw2]J)TO  
`6BQ6)7  
Wz#ZkNO  
/* g`~;"%u7cn  
**TestMethod.java 2wa'WEx  
*/ 9i D&y)$"  
package NetFox; v^;vH$B  
..w$p-1  
" t?44[  
public class TestMethod { Hz=s)6$ey  
*?VB/yO=0  
$ab{GxmX'4  
public TestMethod() Sj IDzNI5  
{ ///xx/weblogic60b2_win.exe z2Z}mktP  
try{ .EvP%A m  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h)aLq  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k=G c#SD5_  
SiteFileFetch fileFetch = new SiteFileFetch(bean); nU0##  
fileFetch.start(); @H^\PH?pp  
} x=X&b%09  
catch(Exception e){e.printStackTrace ();} r?dkE=B  
bR$5G  
J% ZM V  
} F5OQM?J  
a54S,}|  
na 0Zb  
public static void main(String[] args) mX, @yCI  
{ er2;1TW3E  
new TestMethod(); EfkBo5@Qi  
} M:L-j{?y_  
} v- p8~u1N  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
10+5=?,请输入中文答案:十五