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
  • 11327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
/* RCqd2$K"J+  
**SiteFileFetch.java ;F_pF+&q  
*/ ,>p1:pga  
package NetFox; aS! If>  
import java.io.*; y5{Vx{V"Q  
import java.net.*; LWdA3%   
J?C#'2 /   
n58yR -"  
public class SiteFileFetch extends Thread { fI v?HD:j  
Ce/l[v  
8bJj3vr  
SiteInfoBean siteInfoBean = null; //文件信息Bean MxgJ+  
long[] nStartPos; //开始位置 zq(4@S-TU  
long[] nEndPos; //结束位置 zm!M'|~@7  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 4`e[gvh  
long nFileLength; //文件长度 C4aAPkcp2$  
boolean bFirst = true; //是否第一次取文件 lrjVD(R=g  
boolean bStop = false; //停止标志 $c {fPFe-  
File tmpFile; //文件下载的临时信息 ~&< Ls  
DataOutputStream output; //输出到文件的输出流 g@2KnzD  
$GR rTC!  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 9?iA~r|+  
public SiteFileFetch(SiteInfoBean bean) throws IOException Kn=0AdM  
{ w,i?e\5  
siteInfoBean = bean; l*.u rG  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); KCIya[$*  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Y&<]:)  
if(tmpFile.exists ())  j iejs*  
{ S6g_$ Q7  
bFirst = false; h! Bg} B~  
read_nPos(); eDsB.^|l  
} j1rR3)oP  
else q|{z9V<  
{ ,!40\"A  
nStartPos = new long[bean.getNSplitter()]; Z;<:=#  
nEndPos = new long[bean.getNSplitter()]; KKq%'y)u^  
} $cW t^B'  
ck< `kJ`b  
P;`Awp?  
D0Mxl?S?  
} &,P; 7R  
a&2UDl%K  
I_m3|VCa|t  
public void run() 5Gs>rq" #  
{ G@KDRv  
//获得文件长度 TSD7R  
//分割文件 8@[S,[  
//实例FileSplitterFetch RFLfvD<  
//启动FileSplitterFetch线程 IH&0>a  
//等待子线程返回 -=cm7/X  
try{ <+-=j  
if(bFirst) n2 can  
{ q9wObOS$  
nFileLength = getFileSize(); !1Hs;K  
if(nFileLength == -1) ?fN6_x2e3  
{ 's.e"F#  
System.err.println("File Length is not known!"); m lxtey6H3  
} Y&1N*@YP  
else if(nFileLength == -2) '?jsH+j+  
{ tI@aRF=p]2  
System.err.println("File is not access!"); iZLy#5(St  
} '4Jf[  
else #M||t|9iu?  
{ l$Vy\CfK3n  
for(int i=0;i<nStartPos.length;i++) A%2B3@1'q  
{ HC} vO0X4  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); \HIBnkj)3n  
} 1c{m rsB  
for(int i=0;i<nEndPos.length-1;i++) }N} Js*  
{ p+8o'dl8=  
nEndPos = nStartPos[i+1]; IG{ lr  
} :%z#s  
nEndPos[nEndPos.length-1] = nFileLength; zYP6m3 n  
} \FUMfo^  
} 6J\ 2 =c`  
P-a8S*RRa  
\WBO(,]V  
//启动子线程 >|z:CX$]  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tz8 fZ*n  
for(int i=0;i<nStartPos.length;i++) 8k3y"239t  
{ z#Fel/L`O  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q 'd]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]ag{sU@#  
nStartPos,nEndPos,i); |{Ex)hkw  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x|yJCs>  
fileSplitterFetch.start(); EjFn\|VK  
} }`2a>N: &  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z;V(YK(WO.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {_-T!yb  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w\MWr+4  
nEndPos = " + nFileLength); 4/%fpU2  
// fileSplitterFetch[nPos.length-1].start(); t V( WhP  
I eJI-lo  
>|c?ZqW  
//等待子线程结束 2*<Zc|uNW  
//int count = 0; 8h0CG]  
//是否结束while循环 ilde<!?  
boolean breakWhile = false; ImG8v[Q E  
hsQDRx%H}  
;<q 2  
while(!bStop) ! d<R =L  
{ =%<, ^2o  
write_nPos(); uJCp  
Utility.sleep(500); "AZ|u#0P  
breakWhile = true; bZ1*:k2  
7)]boW~Q  
\I:27:iAL  
for(int i=0;i<nStartPos.length;i++) P JATRJ1.  
{ nShXY6bA  
if(!fileSplitterFetch.bDownOver) pbEWnx_  
{ g<(!>:h  
breakWhile = false; 0VcHz$ 6  
break; "b~C/-W I  
} umWs8-'Uw  
} p:TE##  
if(breakWhile) c+&Kq.~K  
break; ?$K-f:?c  
V]; i$  
ZT@=d$Z&t  
//count++; ?IYu"UO<)|  
//if(count>4) zzhZ1;\  
// siteStop(); E& .^|<n  
} D h;5hu2"  
R;!@ xy  
\H bZ~I-  
System.err.println("文件下载结束!"); U+qyS|i  
}  {ibu 0  
catch(Exception e){e.printStackTrace ();} vRH^en  
} r}&&e BY f  
FJDC^@Ne  
J{^md0l  
//获得文件长度 Mib .,J~  
public long getFileSize() eM_;rMCr}  
{ [:.wCG5  
int nFileLength = -1; !p/SX>NJ  
try{ i_Hm?Bi!F  
URL url = new URL(siteInfoBean.getSSiteURL()); { PX&#,_  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J/'Fj?  
httpConnection.setRequestProperty("User-Agent","NetFox"); g kO^J{_@q  
&n;*'M  
Bkd$'7UT  
int responseCode=httpConnection.getResponseCode(); )-_^vB  
if(responseCode>=400) ~;3#MAG  
{ IK\~0L;ozE  
processErrorCode(responseCode); =X?fA,  
return -2; //-2 represent access is error O_8 SlW0e  
} ",3v%$ >  
6w7;  
Nna.NU1  
String sHeader; /^AH/,p  
B;ek a[xU  
]CF-#q}'  
for(int i=1;;i++) ppRmC,0f^  
{ : c~SH/qS  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TL2E|@k1]  
//Utility.log(in.readLine()); @>Yd6C  
sHeader=httpConnection.getHeaderFieldKey(i); y62f{ks_/  
if(sHeader!=null) sJ|pR=g)!  
{ <4LJ #Fx  
if(sHeader.equals("Content-Length")) z )'9[t  
{ h40;Q<D  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 84QOW|1  
break; a$|U4Eqo  
} EW*sTI3  
} v1 8<~  
else #vBrRHuA#"  
break; n#g_)\  
} ;.uYWP|9  
} #+1|O;PB#  
catch(IOException e){e.printStackTrace ();} 3/`BK{  
catch(Exception e){e.printStackTrace ();} (p{%]M  
).;{'8Q  
e&;e<6l&{  
Utility.log(nFileLength); ]0."{^ksL  
UsyNn39  
Ob/)f)!!  
return nFileLength; y017 B<Ou  
} -*' ?D@l  
4>=M"D hB  
BQ0?B*yqd  
//保存下载信息(文件指针位置) >8_y-74  
private void write_nPos() 7A\`  
{ ?YW~7zG  
try{ 3W7^,ir  
output = new DataOutputStream(new FileOutputStream(tmpFile)); QMBT8x/+_'  
output.writeInt(nStartPos.length); bFX{|&tHU  
for(int i=0;i<nStartPos.length;i++) KAClV%jP  
{ M YF ^zheD  
// output.writeLong(nPos); /eQAGFG  
output.writeLong(fileSplitterFetch.nStartPos); p75o1RU  
output.writeLong(fileSplitterFetch.nEndPos); S/XU4i:aV  
} aDdGhB  
output.close(); @}H u)HO  
} ;stuTj@vH  
catch(IOException e){e.printStackTrace ();} k`m7j[A]l  
catch(Exception e){e.printStackTrace ();} +r3)\L{U  
} Bib<ySCre  
mcV<)UA}  
)$:1e)d  
//读取保存的下载信息(文件指针位置) eL SzGbKf  
private void read_nPos() -x+3nb|.  
{ <2U@O` gC  
try{ A4tk</A  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t Ly:F*1i  
int nCount = input.readInt(); ^xa, r#N:V  
nStartPos = new long[nCount]; R'v~:wNTNs  
nEndPos = new long[nCount]; &IQ=M.!r  
for(int i=0;i<nStartPos.length;i++) uI-T]N:W8x  
{ P+j=]Yg  
nStartPos = input.readLong(); 9~Dg<wQ  
nEndPos = input.readLong(); z ?\it(  
} KQPu9f9  
input.close(); lAU99(GXV  
} .rtA sbp.!  
catch(IOException e){e.printStackTrace ();} L~6%Fi&n4  
catch(Exception e){e.printStackTrace ();} BTkx}KK  
} (  zo7h  
G]=z ![$  
_Q5mPBO  
private void processErrorCode(int nErrorCode) ~</FF'Xz  
{ !1)aie+p6  
System.err.println("Error Code : " + nErrorCode); ",b:rgpRp  
} 5*%Gh&)  
m8fj\,X  
bp?5GU&Uy  
//停止文件下载 ln82pQD2Y~  
public void siteStop() gyvrQ, u  
{ ,0! 2x"Q=  
bStop = true; a!$kKOK  
for(int i=0;i<nStartPos.length;i++) >B{NxL3->  
fileSplitterFetch.splitterStop(); cj[b^Wv:  
Ks%0!X?3q  
`*8}q!.  
} [7@ g*!+d  
} G}pFy0W\S  
//负责部分文件的抓取 TwkT|Piw S  
**FileSplitterFetch.java &!8 WRJ  
*/ Rml'{S  
package NetFox; (A~7>\r +  
kG>jb!e@(  
;MS.ag#  
import java.io.*; a#j,0FKv  
import java.net.*; IIR+qJ__|  
+Y 7M7  
#|b*l/t8  
public class FileSplitterFetch extends Thread { wm`<+K  
Yj&Sb  
e"04jd/  
String sURL; //File URL <VxA&bb7c  
long nStartPos; //File Snippet Start Position P-\f-FS  
long nEndPos; //File Snippet End Position -+WAaJ(b  
int nThreadID; //Thread's ID a4,V(Hlm  
boolean bDownOver = false; //Downing is over i|^Q{3?o#  
boolean bStop = false; //Stop identical ! UT'4Fs  
FileAccessI fileAccessI = null; //File Access interface Q>{$Aqc,e  
c|?(>  
~tp]a]yV  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t$!zgUJ  
{ nONuw;K  
this.sURL = sURL; rt+4-WuK>  
this.nStartPos = nStart; ,sL'T[tuiU  
this.nEndPos = nEnd; Z Ts*Y,  
nThreadID = id; 8 Rj5~+5  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^@^8iZ  
} [bh?p+V  
40kAGs>_  
?6:qAFw  
public void run() sq'm)g  
{ u} mj)Nk  
while(nStartPos < nEndPos && !bStop) k+h}HCzE  
{ ZE=sw}=  
+KTfGwKt  
(]#^q8)]\9  
try{ /I7V\  
URL url = new URL(sURL); Ugri _  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /z-rBfdy^  
httpConnection.setRequestProperty("User-Agent","NetFox"); S8#0Vo$)a  
String sProperty = "bytes="+nStartPos+"-"; 9\_s&p=:.  
httpConnection.setRequestProperty("RANGE",sProperty); W[&nQW$E  
Utility.log(sProperty); <&E}db  
=2p?_.|'  
(kxS0 ]=  
InputStream input = httpConnection.getInputStream(); oYu xkG  
//logResponseHead(httpConnection); O=o}uB-*6  
(K[{X0T  
T)zk2\u  
byte[] b = new byte[1024]; l?m"o-Gp3  
int nRead; =!\Nh,\eQ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xTAfV N  
{ %%No XW  
nStartPos += fileAccessI.write(b,0,nRead); eQ>Ur2H8n  
//if(nThreadID == 1) p'h'Cz  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _5p$#U`  
} R (f:UC  
}QI \K  
e/D{^*~S  
Utility.log("Thread " + nThreadID + " is over!"); <,~OcJG(   
bDownOver = true; x/s:/YN'  
//nPos = fileAccessI.write (b,0,nRead); | 1B0  
} #*.!J zOg  
catch(Exception e){e.printStackTrace ();} ^OY$ W  
} &hWELZe0vv  
} b-& rMML  
iE'_x$i  
I*-\u  
//打印回应的头信息 8&@=Anc&q  
public void logResponseHead(HttpURLConnection con) m^ xTV-#l@  
{ e)e(f"t6Q  
for(int i=1;;i++) qR@ES J_  
{ Lvf<g}?4  
String header=con.getHeaderFieldKey(i); Z[@ i/. I  
if(header!=null) "uBnK!  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \tgY2 :  
Utility.log(header+" : "+con.getHeaderField(header)); e4YfJd  
else @D9O<x  
break; zB%~=@Q^6  
} 0!\gK <,z  
} \lK?f]qJq  
L~ &S<5?  
fJ Ll-H  
public void splitterStop() g}+|0FTV  
{  %j&vV>2  
bStop = true; +-!3ruwSn  
} d*6f,z2=  
:BxO6@>Xc  
H1-DK+Q:  
} 2U./ Yfk\  
=zn'0g, J4  
dy6zrgxygP  
/* 2? E;(]dQ  
**FileAccess.java 1| sem(t  
*//文件访问(定位,写) n{QyqI  
package NetFox; 08ZvRy(Je<  
import java.io.*; V[.{cY ?6  
C@qWour  
':4ny]F  
public class FileAccessI implements Serializable{ (U 'n1s/X  
12^uu)6Xm,  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <Y)14w%  
RandomAccessFile oSavedFile; oywPPVxj  
long nPos; v/ry" W  
7@{%S~TN  
^JY {<   
public FileAccessI() throws IOException DGJ:#U E  
{ U.TZd"  
this("",0); f,ro1Nke  
} VESvCei  
xC< )]  
Q h@Q6  
public FileAccessI(String sName,long nPos) throws IOException @ 51!3jeu  
{ Oem1=QpaC  
oSavedFile = new RandomAccessFile(sName,"rw"); ~|KqG  
this.nPos = nPos; R6<'J?k  
oSavedFile.seek(nPos); 8$-MUF,  
} 6Jgl"Jw8  
j"jssbu}  
0Px Hf*  
public synchronized int write(byte[] b,int nStart,int nLen) JlSqTfA  
{ yD<#Q\,  
int n = -1; t3$cX_  
try{ $@VJ@JAe  
oSavedFile.write(b,nStart,nLen); OXLB{|hH80  
n = nLen; ~;(\a@ _  
} cEHpa%_5  
catch(IOException e) IEm?'o:  
{ u/W{JPlL  
e.printStackTrace (); ~ T}D#}  
} E zcch1  
"*zDb|v  
}zA|M9%E  
return n; ?Z|y-4 &>  
} _CNXyFw.7  
%>K(IR pMW  
Rc)]A&J  
} UW":&`i  
H'S~GP4D  
m& AbH&;  
/* Cnpl0rV~5  
**SiteInfoBean.java K14.!m  
*/ zDYJe_m ~  
package NetFox; =F[M>o  
*effDNE!  
v_5O*F7)  
public class SiteInfoBean { )-+tN>Bb  
7'+`vt#E  
kYS#P(1  
private String sSiteURL; //Site's URL /;_$:`|/  
private String sFilePath; //Saved File's Path gB#!g@  
private String sFileName; //Saved File's Name ${Lrj}93  
private int nSplitter; //Count of Splited Downloading File ~/4j&IG  
>%"TrAt  
p YCMJK-H  
public SiteInfoBean() {X, -T&  
{//nSplitter的缺省值为5 Rq1 5AR  
//default value of nSplitter is 5 z .lb(xQ  
this("","","",5); >$}Mr%49  
} #p"F$@N   
'5$: #|-  
Il/`#b@h  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fCa lR7!  
{ wOUCe#P|r  
sSiteURL= sURL; '!X`X=  
sFilePath = sPath; pz2E+o  
sFileName = sName; '\H & EJ'  
this.nSplitter = nSpiltter; >a@1y8B  
uYTyR;a  
=2Ju)!%wr  
} -X EK[  
>CCy2W^W  
s,J\nbj0h  
public String getSSiteURL() f[zKA{R  
{ ,9|7{j|u  
return sSiteURL; v 'L"sgW6I  
} d;%~\+)x4  
(|W6p%(  
lS;S:- -F  
public void setSSiteURL(String value) !OV+2suu1  
{ fpNq  
sSiteURL = value; 2wU,k(F_  
} }`whg8 fZ  
'o]}vyz;  
l7ES*==&@0  
public String getSFilePath() cmf*BkS  
{ O,@QGUoA  
return sFilePath; F[ ^ p~u{  
} *[nS*D\:  
<c`,fd8  
L-W*h  
public void setSFilePath(String value) _58&^:/^  
{  Z1H  
sFilePath = value; C 1HNcfa7  
} >taT V_,  
$v{s b,  
wj$3 L3  
public String getSFileName() g[2[ zIB=  
{ C/"Wh=h6  
return sFileName; ORo +]9)Yv  
} tchpO3u,  
MoC/xF&  
NnZ_x>R  
public void setSFileName(String value) a;7gy419<p  
{ blV'-Al  
sFileName = value; d#,   
} TGPdi5Eq  
iaJN~m\ M  
;f3))x  
public int getNSplitter() #"-w;T%b  
{ 1eqFMf  
return nSplitter; '\7&Iz:%  
} +Y~,1ai 5^  
9 LEUj  
$<wU>X  
public void setNSplitter(int nCount) K0^+2lx  
{ %]DJ-7 xE  
nSplitter = nCount; UJX5}36  
} tIX|oWC$q  
} =WOYZ7  
,J-YfL^x6*  
cRPy5['E  
/* JENq?$S  
**Utility.java `Oi6o[a  
*/ n@e|PWu  
package NetFox; $/i;UUd  
doe u`  
( (mNB]sy  
public class Utility { ;#D:S6 L  
M\9p-%"L  
{u7_<G7  
public Utility() [\i1I`7pE  
{ 9%Ftln6  
rFv=j :8  
@h\u}Ee  
} zI>,A|yy  
CI?M2\<g  
//线程睡眠 9%uJ:c?  
public static void sleep(int nSecond) u-Ip*1/wp  
{ 5E|/n(  
try{ +Y^/0=6h  
Thread.sleep(nSecond); eYjr/`>O  
} UD r@  
catch(Exception e) Jqi^Z*PuX  
{ ?< $DQ%bf  
e.printStackTrace (); 0jwex  
} i%_nH"h  
} n47v5.Wn  
b{d@:"  
//日志 t?kbN\,  
public static void log(String sMsg) n|iO)L\9aB  
{ ^RS`q+g  
System.err.println(sMsg); |N>TPK&Xt  
} ?G!DYUK  
q:v&wb%  
of:xj$dQ_  
public static void log(int sMsg) xBcE>^{1.  
{ X6@G)68  
System.err.println(sMsg); Ik|nL#JH]  
} D7x"P-ie  
} HTCn=MZm ?  
>'lte&  
-5yEd>Z  
/* "Tm`V9  
**TestMethod.java /v:+ vh*mS  
*/ X8b= z9  
package NetFox; -d 6B;I<'  
gg%OOvaj5  
O}#h^AU-BS  
public class TestMethod { ] Vbv64M3  
F .JvMy3  
S2fBZ=V8  
public TestMethod() 5eW GX  
{ ///xx/weblogic60b2_win.exe A|d(5{:N  
try{ ;HeUD5Nt6F  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +Te;LJP  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s k_Q\0a  
SiteFileFetch fileFetch = new SiteFileFetch(bean); EWg\\90  
fileFetch.start(); wGf SVA-q\  
} _6 |lw&o07  
catch(Exception e){e.printStackTrace ();} }A%Sx!7~  
*G#W],~0  
3Ga! )  
} anTS8b   
C2</.jeLa  
Wf=D'6w  
public static void main(String[] args) .qCD(XZ+  
{ Ytnk^/Z1L  
new TestMethod(); AA um1xl  
} Rx 4 ;X  
} *1KrI9i  
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
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
10+5=?,请输入中文答案:十五