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
  • 11751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
/* >Z r f}H  
**SiteFileFetch.java MH7 n@.t  
*/ +}[M&D  
package NetFox; 589hfET  
import java.io.*; Dukvi;\  
import java.net.*; jfF   
!tJQ75Hwv  
7uQiP&v  
public class SiteFileFetch extends Thread { N@6+DHt  
BJC$KmGk  
$P rji  
SiteInfoBean siteInfoBean = null; //文件信息Bean j1D 1tn  
long[] nStartPos; //开始位置 z-ns@y(f@X  
long[] nEndPos; //结束位置 &m[ZpJ9  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 .^ djt  
long nFileLength; //文件长度 &8$Gy u  
boolean bFirst = true; //是否第一次取文件 A{X:p3$eN  
boolean bStop = false; //停止标志 o{MF'B #  
File tmpFile; //文件下载的临时信息 4@19_+3  
DataOutputStream output; //输出到文件的输出流  i;B &~  
HueGARS  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ;+C2P@M  
public SiteFileFetch(SiteInfoBean bean) throws IOException PgHe;^?j  
{ 5argw+2s4$  
siteInfoBean = bean; x# MMrV&M  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); W'lejOiw  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); +)$oy]  
if(tmpFile.exists ()) *WMI<w~_  
{ bji5X')~#  
bFirst = false; XNbeYj  
read_nPos(); ,^wjtA 3j8  
} lidVe]>  
else V9`?s0nn^  
{ Pa)'xfQ$Y6  
nStartPos = new long[bean.getNSplitter()]; M18 >%zM  
nEndPos = new long[bean.getNSplitter()]; 5?l8;xe`{f  
} (-S\%,hO  
b:B+x6M  
A; _Zw[  
-So$ f-y  
} R` g'WaDk  
z H|YVg  
dbga >j  
public void run() xB4}9zN s  
{ <8)cr0~zy>  
//获得文件长度 Rp^fY_  
//分割文件 xu%_Zt2/?j  
//实例FileSplitterFetch Dxvizd>VU  
//启动FileSplitterFetch线程 1FA:"0lO  
//等待子线程返回 (}B3df  
try{ E)>.2{]C>  
if(bFirst) >G9YYt~  
{ fM/~k>wl  
nFileLength = getFileSize(); L0\~ K~q  
if(nFileLength == -1) /aV;EkyO,  
{ f?JP=j  
System.err.println("File Length is not known!"); ?kM2/a"{G  
} ]C'^&:&<  
else if(nFileLength == -2) 4yK{(!&i+  
{ +L0Jje>Az  
System.err.println("File is not access!"); {<cL@W  
} B)/L[ )S  
else E4N/or  
{ y:',)f }  
for(int i=0;i<nStartPos.length;i++) s,CN<`/>x  
{ x`:c0y9uG  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); q!;u4J  
} )&6ZgRq  
for(int i=0;i<nEndPos.length-1;i++)  LA]UIM@  
{ 6L<Y   
nEndPos = nStartPos[i+1]; jWL%*dJrN  
} JIc(hRf9>  
nEndPos[nEndPos.length-1] = nFileLength; H|)F-aL[  
} *Z8qd{.$q  
} Uee(1  
S:lie*Aux*  
eC{St0  
//启动子线程 8AVtUU  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A Xpg_JC  
for(int i=0;i<nStartPos.length;i++) .QU]  
{ x?7z15\  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v? Zo5uVoq  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DuQW?9^232  
nStartPos,nEndPos,i); {h*)|J  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -{XDQ{z<%  
fileSplitterFetch.start(); ZS<`.L6B3  
} nV:RL|p2jw  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KwHlpW*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XvSng"f.  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", icK$W2<8mg  
nEndPos = " + nFileLength); (nu;o!mo9  
// fileSplitterFetch[nPos.length-1].start(); 4iDqd  
XEBeoOX/  
dI+Y1Vq  
//等待子线程结束 _]v@Dq VP  
//int count = 0; x,NV{uG$n  
//是否结束while循环 8'PK}heBU  
boolean breakWhile = false; 2#(dfEAy  
m Ce"=[  
WES$B7y  
while(!bStop) 2kcDJ{(  
{ S2jn  pf}  
write_nPos(); Q7#t#XM  
Utility.sleep(500); W m&*  
breakWhile = true; 0`/CoP<U  
Q{|_"sfJ  
dv Vz#  
for(int i=0;i<nStartPos.length;i++) <v6W l\  
{ $[g#P^  
if(!fileSplitterFetch.bDownOver) 1'!D   
{ F%f)oq`B  
breakWhile = false; _lDNYpv  
break; m[CyvcF*u  
} B.C:06E5  
} d#HlO}  
if(breakWhile) !k Heslvi  
break; pAws{3(Q  
2w}l!'ue  
2>[xe  
//count++; <naxpflom0  
//if(count>4) i A<'i8$P  
// siteStop(); j&u/T  
} sXmP<c  
@'A0Lq+#  
F/PH=Dk  
System.err.println("文件下载结束!"); ]O>AD 6P  
} u9m ~1\R*  
catch(Exception e){e.printStackTrace ();} ce [ Maw  
} |xF!3GGms  
OZ33w-X<  
9#>nFs"H  
//获得文件长度 #KNl<V+c}1  
public long getFileSize() 0|<9eD\I=  
{ vb| d  
int nFileLength = -1; BRa9j:_b  
try{ ^xgqs $`7  
URL url = new URL(siteInfoBean.getSSiteURL()); Vr@tSc&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R$p(5>#\5  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3Vbt(K  
CZE!@1"<{  
on;>iKta9  
int responseCode=httpConnection.getResponseCode(); FJ{/EloF  
if(responseCode>=400) &2Ef:RZF  
{ gA`QV''/:  
processErrorCode(responseCode); JZK93R  
return -2; //-2 represent access is error 7GTDe'T  
} v>HOz\F  
CH#K0hi  
W~PMR/^i  
String sHeader; Yw yMC d  
rog1  
A2ufET  
for(int i=1;;i++) q65]bs4M  
{ $Dd-2p   
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mE=Ur  
//Utility.log(in.readLine()); ?6]B6  
sHeader=httpConnection.getHeaderFieldKey(i); ~%2yDhdQ  
if(sHeader!=null) + MD84YR  
{ 'N^*,  
if(sHeader.equals("Content-Length")) 7n?yf_ je  
{ Z- t&AH  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XjdHH.) S  
break; {\vVzy,t7  
} :T|9;2  
} V;W{pd-I  
else %NfXe[T  
break; 3yw$<lm  
}  +hKs  
} `!spi=f  
catch(IOException e){e.printStackTrace ();} =av0a !  
catch(Exception e){e.printStackTrace ();} ;l1.jQh  
8rx|7  
as'yYn8  
Utility.log(nFileLength); rW090Py  
Bd7B\zM  
^BM !TQ%!  
return nFileLength; 8;L;R ~Q  
} PxQQfI>  
,"KfZf;?  
]Y-Y.&b7t  
//保存下载信息(文件指针位置) |N^"?bSt  
private void write_nPos() Qwt0~9n(  
{ ZJenwo  
try{ g ?xD*3 <  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4U_+NC>b  
output.writeInt(nStartPos.length); 73]8NVm  
for(int i=0;i<nStartPos.length;i++) F,A+O+  
{ g$jTP#%b  
// output.writeLong(nPos); yXoNfsv  
output.writeLong(fileSplitterFetch.nStartPos); FZW`ADq]  
output.writeLong(fileSplitterFetch.nEndPos); =36fS/Gb  
} K a& 2>F  
output.close(); PO8Z2"WI  
} Z#B}#*<C  
catch(IOException e){e.printStackTrace ();} ; o Y|~  
catch(Exception e){e.printStackTrace ();} |d&C<O;f  
} I`*5z;Q!%@  
S0Io$\ha  
kz1#"8Zd!  
//读取保存的下载信息(文件指针位置) /a<UKh:A[  
private void read_nPos() Kc95yt  
{ 7y&6q`y E  
try{ nu7 R  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [^?i<z{0C  
int nCount = input.readInt(); Z'>UR.g  
nStartPos = new long[nCount]; ;HH%OfQq  
nEndPos = new long[nCount]; G<=I\T'g;  
for(int i=0;i<nStartPos.length;i++) Y<u%J#'[  
{ /Jc{aw  
nStartPos = input.readLong(); 8nu!5 3  
nEndPos = input.readLong(); Pc=ei  
} 0O,;[l  
input.close(); !mTq6H12 !  
} LSA6*Q51  
catch(IOException e){e.printStackTrace ();} !'~Ldl  
catch(Exception e){e.printStackTrace ();} /8Y8-&K0  
} FZn1$_Svr  
 ?ueL'4Mm  
]hS<"=oj  
private void processErrorCode(int nErrorCode) Z$g'h1,zW  
{ -3i(N.)<;  
System.err.println("Error Code : " + nErrorCode); AWi>(wk<  
} c+E\e]{  
T7 "QwA  
qD4s?j-9  
//停止文件下载 ~?Vod|>  
public void siteStop() n@ SUu7o  
{ %3~ miP  
bStop = true; qR!ZtJ5j  
for(int i=0;i<nStartPos.length;i++) [uHU[ sG  
fileSplitterFetch.splitterStop(); Z{BK@Q4z  
R.*;] R>M  
<W!nlh  
} @2L^?*n=  
} R;pW,]}g,  
//负责部分文件的抓取 xjiV9{w  
**FileSplitterFetch.java z/`+jIB  
*/ l^ay* H  
package NetFox; ?8{Os;!je  
x'|9A?ez@Z  
Jk-WD"J6  
import java.io.*; $x`HmL3Sb  
import java.net.*; !L{mE&  
3e;|KU   
/KWdIP#  
public class FileSplitterFetch extends Thread { sZCK?  
?wPTe^Qtv  
#7Q9^rG  
String sURL; //File URL D.:`]W|  
long nStartPos; //File Snippet Start Position vT0Op e6m  
long nEndPos; //File Snippet End Position }=)u_q  
int nThreadID; //Thread's ID TK18U*z7J  
boolean bDownOver = false; //Downing is over 'g,_lF  
boolean bStop = false; //Stop identical gJX"4]Ol#}  
FileAccessI fileAccessI = null; //File Access interface __xmn{{L6P  
o]4BST(A  
.pWRV<25  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b#p0s?*  
{ uP%VL}% 0  
this.sURL = sURL; ed/B.SY  
this.nStartPos = nStart; v~Dobk/n  
this.nEndPos = nEnd; F?R6zvive  
nThreadID = id; ?_d>-NC  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8|{ZcW  
} 8tR6.09'  
J)B3o$  
L!l?tM o  
public void run() o.NU"$\?  
{ &4|]VOf  
while(nStartPos < nEndPos && !bStop) lqv}~MC  
{ Q2Ey RFT  
? OF $J|h  
1="]'!2Is  
try{ fqbeO9x  
URL url = new URL(sURL); VnSO>O  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9) ]`le  
httpConnection.setRequestProperty("User-Agent","NetFox"); eA(\#+)X `  
String sProperty = "bytes="+nStartPos+"-"; Ncbe{}<md  
httpConnection.setRequestProperty("RANGE",sProperty); O0z-jZ,])  
Utility.log(sProperty); h ChO  
]}].A q  
@xBb|/I  
InputStream input = httpConnection.getInputStream(); 9ThsR&h3  
//logResponseHead(httpConnection); Qx E%C  
ty~Sf-Pri  
O4f9n  
byte[] b = new byte[1024]; Lf ^ 7|  
int nRead; Y=<ABtertS  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~FYC'd  
{ yC5>k;/6#K  
nStartPos += fileAccessI.write(b,0,nRead); 6wB !dl  
//if(nThreadID == 1) ef{Hj[8  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G@D;_$a  
} eWm'eO  
<:/aiX8  
#UymD-yII  
Utility.log("Thread " + nThreadID + " is over!"); Z"Hq{?l9  
bDownOver = true; :RB7#v={  
//nPos = fileAccessI.write (b,0,nRead); *8a[M{-X  
} /G7^l>pa  
catch(Exception e){e.printStackTrace ();} y@*4*46v  
} i: UN  
} C$])q`9  
(AZneK :*  
ld(_+<e  
//打印回应的头信息 / zNVJhC  
public void logResponseHead(HttpURLConnection con) :/=P6b;  
{  8q9 ^  
for(int i=1;;i++) w/o8R3 F  
{ 9m>L\&\_e  
String header=con.getHeaderFieldKey(i); e[T3,2C  
if(header!=null) teDRX13=;  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b}7g>  
Utility.log(header+" : "+con.getHeaderField(header)); ~P,Z@|c4  
else nY1PRX\  
break; xP1D 9   
} aMydeTCHi  
} ZT&[:>upR  
"N%W5[C{  
j^ 8Hjg  
public void splitterStop() 7SkW!5  
{ ,:}VbQ:3I  
bStop = true; md{1Jn"  
} 7 8xiT  
=u9e5n  
U/q"F<?.c  
} $?kTS1I(  
P!9-!+F"  
V e[Kv07  
/* :X9;KoJl-V  
**FileAccess.java GPs4:CIgG  
*//文件访问(定位,写) Rb b[N#p5  
package NetFox; u5qaLHoEP  
import java.io.*; su\Lxv  
O>X!78]#K  
Q"pZPpl&  
public class FileAccessI implements Serializable{ -y&>&D  
u^ wG Vg  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0\ j)!b  
RandomAccessFile oSavedFile; cru&nH*O^  
long nPos; GF<SQHL,  
w"Zws[pm]  
z9AX8k(B6  
public FileAccessI() throws IOException E0r#xmk  
{ :]\-GJV5  
this("",0); * e,8o2C$  
} M#],#o*G  
kbz+6LcV  
2U+wiE|  
public FileAccessI(String sName,long nPos) throws IOException ,5*<C'9  
{ R<h:>.M  
oSavedFile = new RandomAccessFile(sName,"rw"); "wV7PSbM  
this.nPos = nPos; W7V#G(cpU  
oSavedFile.seek(nPos); "[L+LPET  
} =%FhY^-  
_3KfY  
IU}g[O Cu  
public synchronized int write(byte[] b,int nStart,int nLen) ]tK<[8Y  
{ gavf$be  
int n = -1; V,tYqhQ3  
try{ :VRQd}$Pi  
oSavedFile.write(b,nStart,nLen); Q;2k bVWY  
n = nLen; J0@#xw=+  
} ,tFLx#e#  
catch(IOException e) GV)DLHiyxX  
{ Vc|QW  
e.printStackTrace (); Mm"0Ip2"  
} +{ e2TY  
b Oh[(O!  
jvE&%|Ngw  
return n; ,}OQzK/"mP  
} ",E$}= ,Z  
P'5Q}7  
$kQQdF  
} 8`w#)6(V  
#)%dG3)e  
+N:M;uTS  
/* y7 W7270)  
**SiteInfoBean.java PsS8b  
*/ 3 _DJ  
package NetFox; y=y#*yn&  
kvt"7;(  
5m6I:s`pK  
public class SiteInfoBean { s)~H_,  
c$%I^f}'  
6k\8ulHw  
private String sSiteURL; //Site's URL 7LW %:0  
private String sFilePath; //Saved File's Path \9.@T g8`  
private String sFileName; //Saved File's Name v.H@Ey2  
private int nSplitter; //Count of Splited Downloading File ~{yQsEU  
"g;}B"rG  
K&vqk/JW1  
public SiteInfoBean() V@ph.)z  
{//nSplitter的缺省值为5 =G/`r!r*0I  
//default value of nSplitter is 5 H 4W4# \M  
this("","","",5); n<7R6)j6  
} r?n3v[B  
*3Ci4\Ew  
.sPa${  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ba|76OBRJ  
{ $k3l[@;hE  
sSiteURL= sURL; -f[95Z3}  
sFilePath = sPath; ^5gB?V,  
sFileName = sName; gtb,}T=1  
this.nSplitter = nSpiltter; mt3j$r{_  
7;:Uv=  
o>4GtvA*  
} Q(YQ$ i"S  
2Yd;#i)  
DKf:0E8  
public String getSSiteURL() >_?Waz %  
{ (V+iJ_1g{  
return sSiteURL; +D+Rf,D  
} w=75?3c7F  
6~6*(s|]A  
6Yx/m  
public void setSSiteURL(String value) {f)"F;]V  
{ j%s:d(H`  
sSiteURL = value; 3LD`Ep   
} 6oLq2Z8uP  
y{\K:    
?qjlWCV|e  
public String getSFilePath() !+I!J s"  
{ q ]o ^Y  
return sFilePath; |b:91l  
} , 8F(R%v  
 ZzuWN&  
z@em1W0?Z  
public void setSFilePath(String value) d_}q.%*  
{ 2r&T.  
sFilePath = value; r$Ck:Q}  
} < ekLL{/O'  
d>NM4n[h8  
R~DZY{u+/$  
public String getSFileName() 7vs>PV  
{ kFHtZS(  
return sFileName; "Dwaq*L  
} n$y)F} .-  
4!KUPgg  
qBIKJ  
public void setSFileName(String value) ?KfV>.()  
{ j5>3Td.  
sFileName = value; v= I 'rx  
} 07L 1 "  
/"<o""<]  
$>fMu   
public int getNSplitter() ^h@1tFF  
{ : |?nz$  
return nSplitter; As7Y4w*+  
} mN:p=.& <  
1tQl^>r16  
?N*|S)BN  
public void setNSplitter(int nCount) r8E)GBH-|  
{ AR-&c 3o  
nSplitter = nCount; Xy(o0/7F9  
} 7 a}qnk %  
} \{ui{8+G  
2,X~a;+  
ESl</"<J  
/* $NtbI:e{  
**Utility.java _*O^|QbM  
*/ +5+?)8Ls  
package NetFox; 4>&%N\$*  
^l4=/=RR  
.:b|imgiv  
public class Utility { -C|1O%.  
>f$>Odqe  
y J&`@gB  
public Utility() p|z\L}0  
{ ^sp+ sr :  
M6P`~emX2  
@;we4G5  
} Sp=6%3fZ]m  
[l2ds:  
//线程睡眠 gz?]]-H  
public static void sleep(int nSecond) 1 f;k)x  
{ E$'Zd,|f=  
try{ OA_Bz"  
Thread.sleep(nSecond); 5:ZM-kZT  
} ']hB_ 4v  
catch(Exception e)  Wb/q&o  
{ Ty21-0 F  
e.printStackTrace (); H7KcPN(0  
} sacaL4[_<  
} jz%%r Q(  
i0%S6vmaS  
//日志 7aJLC!  
public static void log(String sMsg) L/,W  
{ f"j"ZM{~U  
System.err.println(sMsg); :i&ZMH,O  
} jcWv&u|  
^hhJ6E_W  
MW^,l=kqW)  
public static void log(int sMsg) ZV`D} CQ  
{ %C!u/:.Kv  
System.err.println(sMsg); EhkvC>y  
} h$Z_r($b  
} ix<sorR H  
k#I4^  
hDp -,ag{  
/* JwNG`M Gc  
**TestMethod.java K>2mm!{  
*/ yE(>R(^  
package NetFox; a+TlZE>8  
q89#Ftkt  
ztNm,1pnQ  
public class TestMethod { `43`*=  
 Sxrbhnx  
4,!S?:7  
public TestMethod() )pS1yYLj  
{ ///xx/weblogic60b2_win.exe 4|ryt4B  
try{ aD aQ 7i  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0B^0,d(s  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CF`tNA3fxm  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Lzzf`jN]  
fileFetch.start(); S(^*DV  
} ]OE{qXr{  
catch(Exception e){e.printStackTrace ();} 0jsU^m<g  
9OeY59 :  
\>8"r,hG|  
} +1Ha,O k  
li4rK <O  
Ng?n}$g*  
public static void main(String[] args) f-N:  
{ 2t3'"8xJ  
new TestMethod(); )SMS<J  
} %t&5o>1C  
} AR i_m  
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
如果您提交过一次失败了,可以用”恢复数据”来恢复帖子内容
认证码:
验证问题:
10+5=?,请输入中文答案:十五