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
  • 11369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
/* _Xcn N:Rt  
**SiteFileFetch.java Kn;D?ioY  
*/ d(`AXyw  
package NetFox; '])2k@o@  
import java.io.*; O\KQl0*l\\  
import java.net.*; F/c$v  
(@0O   
'T=~jA7SkT  
public class SiteFileFetch extends Thread { E; $+f  
:aLT0q!K  
6.1)IQkO  
SiteInfoBean siteInfoBean = null; //文件信息Bean u"xJjS  
long[] nStartPos; //开始位置 K0pac6]  
long[] nEndPos; //结束位置 sM[I4 .A3  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 _6@hTen`  
long nFileLength; //文件长度 UaG1c%7?X  
boolean bFirst = true; //是否第一次取文件 3riw1r;Q  
boolean bStop = false; //停止标志 UYP9c}_,4  
File tmpFile; //文件下载的临时信息 _jU5O;  
DataOutputStream output; //输出到文件的输出流 Ter :sge7  
zvc`3  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) zSvgKmNY  
public SiteFileFetch(SiteInfoBean bean) throws IOException *u6Y8IL1  
{ (h-*_a}F4  
siteInfoBean = bean; ,Tagj`@bHc  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); oB1>x^  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); gR^>3n'  
if(tmpFile.exists ()) ~ (On|h  
{ LjFqZrH  
bFirst = false; t`'iU$:1f  
read_nPos(); 4\ c,)U}  
} q"qo.TPh|$  
else E\ 8  
{ b,TiMf9},h  
nStartPos = new long[bean.getNSplitter()]; 1SIq[1  
nEndPos = new long[bean.getNSplitter()]; r,P1^uHx  
} LA3<=R]  
)D-c]+yt  
 _?vo U  
<|Yj%f  
} &hIRd,1#  
M6r^L6$N  
<+#o BN  
public void run() kUx&pYv  
{ 3-Dt[0%{  
//获得文件长度 w2O!M!1  
//分割文件 2L_6x<u'  
//实例FileSplitterFetch =,!\~`^  
//启动FileSplitterFetch线程 /2M.~3gQ  
//等待子线程返回 \<0B1m  
try{ DciwQcG  
if(bFirst) =VLS/\A  
{ x3ERCqTR  
nFileLength = getFileSize(); cV{%^0? D  
if(nFileLength == -1) C8#@+Q.  
{ o ]Jv;Iy@?  
System.err.println("File Length is not known!"); s{ V*1$e~  
} ]maYUKqv}'  
else if(nFileLength == -2) UgB'[@McS  
{ 2>} xhQJ  
System.err.println("File is not access!"); C^t(^9  
} =S[yE]v^  
else 0Iud$Lu  
{ ?::NO Dg  
for(int i=0;i<nStartPos.length;i++) w(L>#?  
{ ^1:U'jIXO  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); oIGrA-T}  
} ~zm 7?_"@]  
for(int i=0;i<nEndPos.length-1;i++) jUj<~:Q}3o  
{ TGuiNobD  
nEndPos = nStartPos[i+1]; V~GWl1#7  
} 1%M&CX  
nEndPos[nEndPos.length-1] = nFileLength; b1pQ`qt  
} CV$],BM  
} at!Y3VywG  
l ?Y_~Wuw  
^^i6|l1  
//启动子线程 *?QE2&S:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3QI?[R.  
for(int i=0;i<nStartPos.length;i++) %xwIt~Y  
{ )Fd HV;K  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rQ4*k'lA:  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4fh^[\  
nStartPos,nEndPos,i); 0s#vwK13  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }MR1^  
fileSplitterFetch.start(); 7;.xc{  
} -Z4{;I[Q@  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +u@aJ_^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X.ONa_  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2c<&eX8"  
nEndPos = " + nFileLength); $=sXAK9   
// fileSplitterFetch[nPos.length-1].start(); IUGz =%[  
A>VI{  
?6Cz[5\  
//等待子线程结束 rdJm{<  
//int count = 0; |5I'CNi\  
//是否结束while循环 xy+QbD T  
boolean breakWhile = false; "O+5R(XT  
nmlPX7!{$  
E{=2\Wkcp  
while(!bStop) _2fkb=2@  
{ 0,*%vG?Q  
write_nPos(); qP!eJ6[Nh"  
Utility.sleep(500); P ]N [y  
breakWhile = true; Jxf~&!zR  
z^o1GY  
;vhyhP.oM  
for(int i=0;i<nStartPos.length;i++) A6<C-1 N}j  
{ He0=-AR8  
if(!fileSplitterFetch.bDownOver) O <9~Kgd8h  
{ !DjvsG1x  
breakWhile = false; `\=Gp'&Q+  
break; g}&hl"j  
} z2ms^Y=j  
} v/uO&iQw5  
if(breakWhile) t<uYM  
break; %v5R#14[n  
g1(Xg.  
RhF>T&Q  
//count++; #gQF'  
//if(count>4) qv 3^5 d  
// siteStop(); Q_*_?yf  
} 5OM?3M  
z;]CmR@Ki  
sK$wN4k  
System.err.println("文件下载结束!"); /4=-b_2Y~  
} Ocg"M Gb  
catch(Exception e){e.printStackTrace ();} L^kp8o^$  
} VeiElU3  
u]C`6)>  
(A k\Lm  
//获得文件长度 >QQ(m\a$  
public long getFileSize() -y) ,Y |  
{ kg5ev8  
int nFileLength = -1; k>4qkigjc  
try{ 5G}6;UY  
URL url = new URL(siteInfoBean.getSSiteURL()); h>S[^ -,  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ofc.zwH  
httpConnection.setRequestProperty("User-Agent","NetFox"); $<@\-vYvr@  
!Gs} tiMH  
}pNX@C#De  
int responseCode=httpConnection.getResponseCode(); Z{-Lc68  
if(responseCode>=400) xIbMs4'iEx  
{ XR# ;{p+b  
processErrorCode(responseCode); 8$P>wCK\l  
return -2; //-2 represent access is error KM?1/KZ/~  
} 4C_c\;d  
.;/L2Jv  
&!.HuRiuC  
String sHeader; iCG`3(xL  
!jX4`/n2  
Z%o7f6P0IX  
for(int i=1;;i++) `hh9"Ws%  
{ $FM' 3%B[  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e&Y0}oY  
//Utility.log(in.readLine()); A//?6O Jx?  
sHeader=httpConnection.getHeaderFieldKey(i); dFW=9ru+MQ  
if(sHeader!=null) c|p,/L09L  
{ O_@2;iD^^  
if(sHeader.equals("Content-Length")) V}8$p8#<@  
{ kka"C]!  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pck>;V  
break; -<f/\U  
} =6%|?5G  
} ,krS-.  
else ~&G4)AM  
break; w*LbH]l<-  
} ,cHU) j  
} j\)H  
catch(IOException e){e.printStackTrace ();} `"y`AY/N  
catch(Exception e){e.printStackTrace ();} )na&" bJ  
D!> d0k,Y  
QEJGnl676  
Utility.log(nFileLength); _g|acBF  
h* .w"JO  
Ueyw;Y  
return nFileLength; jp<VK<s]  
} &~~s6   
f@z*3I;  
@ RR\lZ  
//保存下载信息(文件指针位置) Hhv$4;&X  
private void write_nPos() ," R>}kPli  
{ mBl7{w;Iv  
try{ /A(NuB<Pq  
output = new DataOutputStream(new FileOutputStream(tmpFile)); pG yRX_;  
output.writeInt(nStartPos.length); &sOM>^SAD  
for(int i=0;i<nStartPos.length;i++) H~9=&p[Q  
{ F-0UdV  
// output.writeLong(nPos); %xg"Q |  
output.writeLong(fileSplitterFetch.nStartPos); 'Ji+c  
output.writeLong(fileSplitterFetch.nEndPos); /8eW@IO.F  
} jXIEp01  
output.close(); s44iEh=V(I  
} {yq8<?  
catch(IOException e){e.printStackTrace ();} |-kEGLH[*V  
catch(Exception e){e.printStackTrace ();} 'U)8rR  
} !IA KVQ  
+WF.wP?y  
tV`&- H  
//读取保存的下载信息(文件指针位置) @-6?i)  
private void read_nPos() 7:o+iP46  
{ c^S&F9/U*  
try{ :C%47qv  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0|C[-ppr  
int nCount = input.readInt(); a$+#V=bA  
nStartPos = new long[nCount]; |=3 *;}  
nEndPos = new long[nCount]; Z=9dMND  
for(int i=0;i<nStartPos.length;i++) @hT;Bo2G]  
{ <xF?~7  
nStartPos = input.readLong(); eTZ`q_LfI1  
nEndPos = input.readLong(); 7Po/_%  
} jOl1_  
input.close(); 3wNN<R  
} 6Bdyf(t  
catch(IOException e){e.printStackTrace ();} Yq;&F0paK  
catch(Exception e){e.printStackTrace ();} tc/jY]'32  
} \X opU"  
>4'21,q  
c~oe, 9  
private void processErrorCode(int nErrorCode) rk|a'&  
{ 0*{p Oe/u  
System.err.println("Error Code : " + nErrorCode); ZOHRUm  
} {G.{a d  
X,53c$  
}rxFS <j  
//停止文件下载 m t.,4  
public void siteStop() v<fWc971  
{ 2$Y3[$  
bStop = true; }q x(z^  
for(int i=0;i<nStartPos.length;i++) bVOO)  
fileSplitterFetch.splitterStop(); 0C7"3l  
I)uASfT$  
4+,*sn  
} 73#9NZ R  
} GD/nR4$  
//负责部分文件的抓取 c$.T<r)Z  
**FileSplitterFetch.java {r X5  
*/ 7x:F!0:  
package NetFox; gU*I;s>  
"lb\c  
CCwK8`%   
import java.io.*; '|+=B u  
import java.net.*; 9 &[\*{  
m&{rBz0  
1 pYsjo~  
public class FileSplitterFetch extends Thread { n7'<3t  
dR?5$V(  
c{ZqQtfM  
String sURL; //File URL ^W{eO@  
long nStartPos; //File Snippet Start Position 3pzOt&T|w  
long nEndPos; //File Snippet End Position /XC;.dLA#  
int nThreadID; //Thread's ID  K oL%}u&  
boolean bDownOver = false; //Downing is over ol1AD: Ho  
boolean bStop = false; //Stop identical [kQ"6wh8  
FileAccessI fileAccessI = null; //File Access interface KN|'|2/|  
/Ir 7 DZK  
| eK,Td%  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~n)]dFy  
{ + >Fv*lux  
this.sURL = sURL; W'8J<VBD  
this.nStartPos = nStart; P/HHWiD`D  
this.nEndPos = nEnd; (p'/p  
nThreadID = id; | H5Ync[s  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LjX&' ,  
} 4_Tb)?L+:  
">rsA&hN-  
+X{cN5Y K  
public void run() R#r h  
{ B&to&|jf  
while(nStartPos < nEndPos && !bStop) K>`m_M"LA  
{ B/[hi%~  
* , |)~$=>  
;g!xQvcR  
try{ pvK \fSr  
URL url = new URL(sURL); )2   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @|JPE%T   
httpConnection.setRequestProperty("User-Agent","NetFox"); /6?tgr  
String sProperty = "bytes="+nStartPos+"-"; t;bZc s  
httpConnection.setRequestProperty("RANGE",sProperty); U!3uaz'  
Utility.log(sProperty); @*AYm-k  
.oW~:mY  
ixoMccU0  
InputStream input = httpConnection.getInputStream(); pRb+'v&_k  
//logResponseHead(httpConnection); _S[Rvb1e   
y81#UD9[  
4C2>0O<^s  
byte[] b = new byte[1024]; }Etd#">  
int nRead; Z)b)v  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wt3Z?Pb  
{ bF8xQ<i~Y  
nStartPos += fileAccessI.write(b,0,nRead); t/EMBfLc  
//if(nThreadID == 1) 4rGO8R  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k1@  A'n  
} "m<eHz]D  
w7.?zb!N  
Gff[c%I  
Utility.log("Thread " + nThreadID + " is over!"); pfT`WT  
bDownOver = true; 'IqK M  
//nPos = fileAccessI.write (b,0,nRead); E: LQ!  
} UlLM<33_)  
catch(Exception e){e.printStackTrace ();} t8a@L(J$  
} HCn ]#  
} D+@/x{wX2  
f"OA Zji  
eO[Cb]Dy:  
//打印回应的头信息 !D|pbzQc8  
public void logResponseHead(HttpURLConnection con) 6#lC(ko'  
{ 0wa!pE"  
for(int i=1;;i++) UVQa af  
{ m}'t'l4 c  
String header=con.getHeaderFieldKey(i); ]R3pBC"Jv  
if(header!=null) \p=W4W/  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JCU3\39}  
Utility.log(header+" : "+con.getHeaderField(header));  h(N 9RJ}  
else E]U3O>hf  
break; <PuB3PEvV  
} Qi'WV9ke  
} h1UlLy 8  
gP hw.e""  
$y]||tX  
public void splitterStop() TF iM[  
{ {dr&46$p  
bStop = true; Hr8$1I$=  
} ff5 Lwf{{  
t5B|c<Hb\  
-GkK[KCH  
} K1wN9D{t'  
q9]^+8UP  
A%czhF  
/* -L4G WJ~.-  
**FileAccess.java A(@gv8e[H^  
*//文件访问(定位,写) D` `NQ`>A  
package NetFox; 8KELN(o$ 7  
import java.io.*; i,b7Ft:F&  
/5'<w(  
LU IT=+  
public class FileAccessI implements Serializable{ o_KcnVQ\  
Z6/~2S@  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V<7K!<g)b  
RandomAccessFile oSavedFile; eYX_V6c  
long nPos; OFL+Q~~C  
0<]!G|;|  
iYQy#kO  
public FileAccessI() throws IOException huD\dmQ:]  
{ _x|8U'|Ce  
this("",0); EKS<s82hF&  
} WUK.>eM0  
GTIfrqT  
IEr`6|X  
public FileAccessI(String sName,long nPos) throws IOException I%b:Z  
{ _M4v1Hr48  
oSavedFile = new RandomAccessFile(sName,"rw"); @`+$d=rO`  
this.nPos = nPos; D}/.;]w<[&  
oSavedFile.seek(nPos); \ui~n:aWJ  
} }b\q<sNE{  
7<'i#E~  
.O-DVW Cm  
public synchronized int write(byte[] b,int nStart,int nLen) w,#W&>+&  
{ 0]w[wc <  
int n = -1; #2'&=?J1r  
try{ ^V,/4u  
oSavedFile.write(b,nStart,nLen); b0=AQ/:  
n = nLen; !J(,M)p!  
} *rKv`nva5  
catch(IOException e) _$_CR\$  
{ )w?$~q  
e.printStackTrace (); RIqxM  
} c(g^*8Pb  
}`FC__  
Uk ;.Hrt.  
return n; Wv/5#_  
} 1% %Tm"  
^X'7>{7Io  
'n.9qxY;  
} lc(iy:z@  
)g^Ewzy^X  
He;%6OG{  
/* PCnJ2  
**SiteInfoBean.java Guc^gq}  
*/ %9)J-B  
package NetFox; w7V W   
`;2`H, G'  
0nnq/u^  
public class SiteInfoBean { buyz>IC P  
(\Zo"x;(  
.u3W]5M|  
private String sSiteURL; //Site's URL +%$V?y (  
private String sFilePath; //Saved File's Path F>R)~;Ja  
private String sFileName; //Saved File's Name &c ~)z\$  
private int nSplitter; //Count of Splited Downloading File <"%h1{V  
\1_&?( pU  
640V&<+v  
public SiteInfoBean() T5+b{qA  
{//nSplitter的缺省值为5 D|#(zjl@  
//default value of nSplitter is 5  Jl,x~d  
this("","","",5); ,Gx=e!-N5  
} [6N39G$  
o-Arfc3Q  
- & r{%7  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter)  Vp4]  
{ E zUjt)wF  
sSiteURL= sURL; G<1mj!{Vp  
sFilePath = sPath; PyE<`E  
sFileName = sName; a8$pc>2E  
this.nSplitter = nSpiltter; 2@rc&Tx  
LK~ 0ck7  
P .(X]+  
} .JjuY'-Q  
'J$NW  
{4*%\?c,n  
public String getSSiteURL() .?NAq[H%  
{ _?<Fc8F  
return sSiteURL; XE\bZc  
} Q)&Ztw<  
x|5/#H  
Pw{+7b$  
public void setSSiteURL(String value) 0l*/_;wo  
{ u1<kdTxA N  
sSiteURL = value; |JQ05nb  
} EZV$1pa  
)cXc"aj@s  
wS4wED&a  
public String getSFilePath() x]T;W&s  
{ ZS]e}]Zwp  
return sFilePath; +a;j>hh  
} =c'LG   
XF6= xD  
hRu%> =7  
public void setSFilePath(String value) gE~31:a^  
{ ,zaveQ~l  
sFilePath = value; eF@E|kK  
} 0M p>X  
~ 5b %~:  
Xqk$[ peS  
public String getSFileName() xB#E&}Ho  
{ Xs/hqIXB  
return sFileName; - _(!  
} xAflcY>Ozs  
19_F\32  
$oEDyC  
public void setSFileName(String value) |%}?*|-  
{ 4w,}1uNEf  
sFileName = value;  Bv3v;^  
} Gex^\gf  
<4Fd ~  
I~I%z'"RQd  
public int getNSplitter() "M tQj}  
{ U&NOf;h$  
return nSplitter; 7~&Y"&  
} ~oI49Q&{  
uH#NJoR O  
?#'qY6 ^  
public void setNSplitter(int nCount) )Jc>l;G(M  
{ 8"@<s?0\"  
nSplitter = nCount; -:QyWw/d  
} h$!qb'|  
} DCm;dh  
C{D2mSS  
>Et?7@   
/* &P;x<7h$t?  
**Utility.java SCo9[EJ  
*/ A28w/ =e7  
package NetFox; I4hr5M3  
#\jPBLc  
vD(;VeW[  
public class Utility { k91Y"_&  
y`N1I  
A;g[G>J  
public Utility() 1^,rS  
{ (T^aZuuS  
w8E,zH  
R =jK3yfw  
} -{< %Wt9  
FUH1Z+9  
//线程睡眠 j04Q3d \f  
public static void sleep(int nSecond) HCP Be2  
{ 7yc:=^ )  
try{ i"b*U5k  
Thread.sleep(nSecond); V=c&QPP  
} kTzZj|l^\  
catch(Exception e) 7fVVU+y  
{ V +hV&|=  
e.printStackTrace (); {S}/LSNB  
} cB<Zez  
} MF1u8Yl:0  
4Qw!YI#40$  
//日志 H'Po  
public static void log(String sMsg) E/am^ TO`  
{ 5/(Dh![l  
System.err.println(sMsg); OZ-F+#d  
} SsaF><{5R  
E 1>3[3  
4b (iGLrt0  
public static void log(int sMsg) f[z#=zv  
{ z*R"917  
System.err.println(sMsg); Wl*\kQ}U  
} IX3r$}4  
} ^EB}e15"  
5$y<nMP  
yyXJ_B  
/* wwF20  
**TestMethod.java 2;q6~Y,  
*/ wp@c;gK7  
package NetFox;  u2DsjaL  
%7{6>6%  
DO0["O74  
public class TestMethod { Z,!Rj7wZ  
{yJ{DU?%Y  
fc M~4yP?  
public TestMethod() ;z&p(e  
{ ///xx/weblogic60b2_win.exe =7$YBCuF  
try{ }g`A*y;t  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R=E )j^<F  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /  ]I]  
SiteFileFetch fileFetch = new SiteFileFetch(bean); h'N,oDB)  
fileFetch.start(); /at#[Pw~01  
} nc`[fy|}  
catch(Exception e){e.printStackTrace ();} ] qrO"X=  
d`2VbZC`  
6~}=? sX4  
} $ biCm$a  
Qx {/izc  
b|4h2iuM  
public static void main(String[] args) 6 Iup4sP  
{ 9g>ay-W[(  
new TestMethod(); ty(F;M(  
} /Cwt4.5  
} YRB,jwne  
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