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
  • 7677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
/* xHv ZV<#  
**SiteFileFetch.java _|kxY '_[8  
*/ 4;e5H_}Oo  
package NetFox; p& y<I6a,  
import java.io.*; AYqX |  
import java.net.*; ey7 f9  
+h|`/ &,  
%(3|R@G.  
public class SiteFileFetch extends Thread { DE}K~}sbd  
+\d56j+D  
t<.)Z-Ii  
SiteInfoBean siteInfoBean = null; //文件信息Bean n{n52][J]  
long[] nStartPos; //开始位置 dk[!V1x4\  
long[] nEndPos; //结束位置 yj 3cyLXw  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 5d Eh7XL  
long nFileLength; //文件长度 SYAyk  
boolean bFirst = true; //是否第一次取文件 Pr':51(  
boolean bStop = false; //停止标志 Q{sH3Y#l  
File tmpFile; //文件下载的临时信息 #xsE3Wj-X  
DataOutputStream output; //输出到文件的输出流 ##,a0s^  
&#{Z( h.de  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 44ek IV+?  
public SiteFileFetch(SiteInfoBean bean) throws IOException W9 GxXPA  
{ !Q2d(H>  
siteInfoBean = bean; XRM_x:+]  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); $v4.sl:x  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); JFcLv=U  
if(tmpFile.exists ()) >*~L28Fyn  
{ :3v}kLO7|  
bFirst = false; vOn`/5-  
read_nPos(); 6 a(yp3  
} dI.WK@W'o  
else w1Nm&}V  
{ M8MR oA6F  
nStartPos = new long[bean.getNSplitter()]; u@W|gLT1  
nEndPos = new long[bean.getNSplitter()]; hO\<%0F  
} .F4>p=r  
GFj{K  
=)0,#9k U]  
}NHaCG[,  
} %<\vGqsM  
mitHT :%r2  
8g@<d ^8@  
public void run() <GS^  
{ q(  
//获得文件长度 1-8mFIK  
//分割文件 dP9qSwTa  
//实例FileSplitterFetch b6 cBg  
//启动FileSplitterFetch线程 -]0OKE&  
//等待子线程返回 =Gpylj7?~  
try{ 5kc/Y/4o  
if(bFirst) f',Op1o  
{ \j@OZ   
nFileLength = getFileSize(); R/~p>apg8  
if(nFileLength == -1) 6dq(T_eG  
{ ne>pOK<vZ  
System.err.println("File Length is not known!"); Nyku4r0  
} (yH'{6g\  
else if(nFileLength == -2) )Kc<j!8-[  
{ $SlIr<'*"  
System.err.println("File is not access!"); %f&/E"M  
} K0u|U`   
else t URu0`](  
{  :|>h7v  
for(int i=0;i<nStartPos.length;i++) G)EU_UE 9  
{ 8zZvht*  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 3@etRd;]Kr  
} \\iQEy<i  
for(int i=0;i<nEndPos.length-1;i++) &PR5q 7  
{ ]~Rho_mq#  
nEndPos = nStartPos[i+1]; JrJo|0Q  
} k KaE=H-x  
nEndPos[nEndPos.length-1] = nFileLength; Vh'P&W?[  
} S] }nm  
} %|s; C  
[`ebM,W  
l.q&D< _  
//启动子线程 vLv@&lMW  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kjTduZ/3 "  
for(int i=0;i<nStartPos.length;i++) {DV_* 5  
{ UFXaEl}R   
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B{QBzx1L9c  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), T;Lkaxsn  
nStartPos,nEndPos,i); w#ZoZZ wh  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5dx$HE&b)  
fileSplitterFetch.start(); -RE^tW*Yy  
} 3atBX5  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), { }:#G  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1h^:[[!c  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m]'#t)B_m  
nEndPos = " + nFileLength); y*4=c _Z  
// fileSplitterFetch[nPos.length-1].start(); :vmH]{R  
GSoX<*i  
RVZ")Z(  
//等待子线程结束 $h+1u$po  
//int count = 0; .T}Wdn g  
//是否结束while循环 QVv#fy1"6  
boolean breakWhile = false; Q 1U\D  
h=W:^@G  
%:M ^4~dc  
while(!bStop) ${<%" hR$  
{ W =D4r  
write_nPos(); 6|gCuT4  
Utility.sleep(500); TJ2=m 9Z  
breakWhile = true; {0[tNth'h  
>BV^H.SO|1  
x) ,eI'mf  
for(int i=0;i<nStartPos.length;i++) ]3D0R;  
{ :N:yLd} &  
if(!fileSplitterFetch.bDownOver) _('=b/  
{ qEyyT[:  
breakWhile = false; Z_LFIz*c  
break; ^P[e1?SZG  
} g?c xp +  
} NN%*b yK  
if(breakWhile) h){0rX@:&  
break; ?k+xSV  
[u =+3b  
X1DF*wI  
//count++; &xU[E!2H%  
//if(count>4) ZJnYIK  
// siteStop(); cutuDZ  
} Q$a{\*[:+  
+! ]zA4x  
6]&OrS[  
System.err.println("文件下载结束!"); .6ylZ  
} evya7^,F  
catch(Exception e){e.printStackTrace ();} 3$jT*OyG#  
} )cX*I gO  
Ab~3{Q]#  
qFicBpB  
//获得文件长度 G'nmllB`]  
public long getFileSize() Q3XpHnufu+  
{ 1rNzJ;'  
int nFileLength = -1; =T3 <gGM  
try{ |.(dq^  
URL url = new URL(siteInfoBean.getSSiteURL()); ]Oe2JfJwx  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [T|aw1SoN  
httpConnection.setRequestProperty("User-Agent","NetFox"); t=BUN  
N+9VYH"*  
)~GmU9f  
int responseCode=httpConnection.getResponseCode(); #%pI(,o=  
if(responseCode>=400) J-[,KME_^  
{ OsTc5K.U~  
processErrorCode(responseCode); H[NSqu.s  
return -2; //-2 represent access is error 7!e vm;A  
} ntu5{L'8  
v3*_9e  
D.r<QO~6B  
String sHeader; 2+RUTOv/d  
yjO1 Ol  
.H escg/S  
for(int i=1;;i++) Rm2yPuOU}A  
{ ~G)S   
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I )~GZ  
//Utility.log(in.readLine()); ;d@#XIS&-(  
sHeader=httpConnection.getHeaderFieldKey(i); 'S20\hwt-  
if(sHeader!=null) 3#W T.4k  
{ h! M  
if(sHeader.equals("Content-Length")) %Si6]3-^@  
{ To\QjP-  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X1:V<,}"  
break; a Fl;BhM  
} i"1Mfz~e  
} O+nEXS\rQ  
else Wt*cIZ  
break; v>6"j1Z  
} JOj;^ h  
} 0B[="rTS7#  
catch(IOException e){e.printStackTrace ();} v|Pv 03%?7  
catch(Exception e){e.printStackTrace ();} bYcV$KJk  
{IjF+@I  
q?H|o(  
Utility.log(nFileLength); Z@yW bjE7Z  
3>3Kwc~E  
D+#E -8  
return nFileLength; *-#&K\  
} Ij 79~pn  
$6qh| >z.  
gLb`pCo/  
//保存下载信息(文件指针位置) 2ElJbN#  
private void write_nPos() ~b(i&DVK  
{ @tF\p  
try{ \|n- O=}=2  
output = new DataOutputStream(new FileOutputStream(tmpFile)); gGR"Z]DBk  
output.writeInt(nStartPos.length); EHSlK5bD,  
for(int i=0;i<nStartPos.length;i++) OP;v bZ  
{ _Mi5g_  
// output.writeLong(nPos); j9m_jv  
output.writeLong(fileSplitterFetch.nStartPos); ~Q*%DRd&Z-  
output.writeLong(fileSplitterFetch.nEndPos); >|J`s~?  
} \0A3]l  
output.close(); hl;u'_AB  
} seba9 y  
catch(IOException e){e.printStackTrace ();} 4aug{}h("  
catch(Exception e){e.printStackTrace ();} [Hx0`Nc K  
} tCw<Ip  
%3s1z<;R[S  
*}Xf!"I#]N  
//读取保存的下载信息(文件指针位置) :Oy%a'w   
private void read_nPos() 36.Z0Z1'F>  
{ ke!?BZx  
try{ 2"COP>  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MO[2~`,Q!  
int nCount = input.readInt(); T!uM+6|Y  
nStartPos = new long[nCount]; QER?i;-wb  
nEndPos = new long[nCount]; H h4WMZJG  
for(int i=0;i<nStartPos.length;i++) \h+AXs<j  
{ JX<)EZ!F  
nStartPos = input.readLong(); ;[(oaK@+n  
nEndPos = input.readLong(); y$;/Vm_'  
} []D&bYpv  
input.close(); cv8L-Z>x.=  
} 3v(*5  
catch(IOException e){e.printStackTrace ();} P i=+/}  
catch(Exception e){e.printStackTrace ();} ;$HftG>B  
} x-XD.qh7Hr  
Z~GL5]S  
},uF 4M.K  
private void processErrorCode(int nErrorCode) f0!))/rSD  
{ 6d:zb;Iz  
System.err.println("Error Code : " + nErrorCode); %Celc#v  
}  Ii6<b6-  
AWcLUe{  
p}&#jE  
//停止文件下载 "<6G6?sz  
public void siteStop() 5CuuG<0  
{ X3(tuqmi  
bStop = true; a,Sw4yJ!Q  
for(int i=0;i<nStartPos.length;i++) |U~<3.:m:  
fileSplitterFetch.splitterStop(); lVd^ ^T*fh  
84$nT>c  
+2(I1  
} iyN:%ofh  
} 02Y]`CXj  
//负责部分文件的抓取 ~Cbc<[}  
**FileSplitterFetch.java AJt+p&I[J  
*/ iky|Tp  
package NetFox; w?3p';C  
ysJQb~2q  
>u>5{4  
import java.io.*; 4Xgg%@C  
import java.net.*; >1s* at/h  
>/{@C  
w2Us!<x  
public class FileSplitterFetch extends Thread { &]V.S7LC #  
Y1L[;)Hn  
Uq[>_"}  
String sURL; //File URL Q_1:tW &  
long nStartPos; //File Snippet Start Position m&xW6!x  
long nEndPos; //File Snippet End Position ``V" D  
int nThreadID; //Thread's ID Y)1PB+  
boolean bDownOver = false; //Downing is over lvdf^b/ j  
boolean bStop = false; //Stop identical 9Q.rMs>qj  
FileAccessI fileAccessI = null; //File Access interface #r$cyV!k  
2$9odD<r  
9 eR-  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *jLJcb*.Ap  
{ tI]Q%S,  
this.sURL = sURL; $:BKzHmg  
this.nStartPos = nStart; l~1Oef#y  
this.nEndPos = nEnd; &]g}u5J!=  
nThreadID = id; -O1>|y2rU  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bNm#tmSt  
} ICpAt~3[M  
jGJLSEe_  
.RE:;<|w  
public void run() 2^Eg9y'  
{ t\?ik6  
while(nStartPos < nEndPos && !bStop) mGtdO/C#B  
{ FFl!\y*0z  
NYt&@Z}]  
s0\X ^  
try{ ? 8)'oMD  
URL url = new URL(sURL); Jk&3%^P{m  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); neB\q[k  
httpConnection.setRequestProperty("User-Agent","NetFox"); 6q*9[<8  
String sProperty = "bytes="+nStartPos+"-"; eS{!)j_^  
httpConnection.setRequestProperty("RANGE",sProperty); k\wW##=v  
Utility.log(sProperty); "76 ]u)  
<W|3\p6  
cq5jPZ}  
InputStream input = httpConnection.getInputStream(); 1G"z<v B  
//logResponseHead(httpConnection); ;}7Rjl#  
l2`s! ,<>O  
"K  ~  
byte[] b = new byte[1024]; [V^WGW2oY  
int nRead; |"?M1*g  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FI[A[*fi  
{ w&X<5'GM  
nStartPos += fileAccessI.write(b,0,nRead); ccB&O _  
//if(nThreadID == 1) pSoiH<33  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +GG9^:<yr  
} 8R2QZXJb-  
Jy^u?  
>5_2_Y$"  
Utility.log("Thread " + nThreadID + " is over!"); a<@1 -j<  
bDownOver = true; ztnFhJ<a$  
//nPos = fileAccessI.write (b,0,nRead); MPCBT!o4Z  
} M:XSQ["6>V  
catch(Exception e){e.printStackTrace ();} U [*FCD!~  
} qT ,Te  
} fg s!v7  
5"^en# ?9  
: imW\@u  
//打印回应的头信息 ?QsQnQ  
public void logResponseHead(HttpURLConnection con) VkvB<3  
{ E4xj?m^(y=  
for(int i=1;;i++) |P[w==AAf  
{ ,eOB(?Ku  
String header=con.getHeaderFieldKey(i); C+'/>=>a.  
if(header!=null) (XeE2l2M  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LyZ.l*h%=m  
Utility.log(header+" : "+con.getHeaderField(header)); zer%W%  
else vBRQp&YwX  
break; J3,fk)  
} !i{aMxUP  
} Z LB4m`  
OPwtV9%  
.}^g!jm~h  
public void splitterStop() j\,EO+ZQCv  
{ L\Aq6q@c  
bStop = true; 9`wZz~hL"  
} <nE>XAI_7  
`q?8A3A  
BZ:H`M`n  
} -- PtZ]Z  
A$<.a'&T!  
@AG n{q  
/* X59: C3c  
**FileAccess.java 0":ib0=  
*//文件访问(定位,写) T29Dt  
package NetFox; JF # # [O  
import java.io.*; mZk]l5Lc  
XR+Y=R  
0C1pt5K  
public class FileAccessI implements Serializable{ o4j[p3$  
cimp/n"  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %{ABaeb]  
RandomAccessFile oSavedFile; d^RxQuA  
long nPos; IHe/xQ@  
#,,d>e  
>{N9kW Y  
public FileAccessI() throws IOException Kh,V.+7k  
{ C3eR)Yh  
this("",0); }x@2]juJ  
} i'4B3  
(0j}-iaQEZ  
s@9vY\5[9  
public FileAccessI(String sName,long nPos) throws IOException { D^{[I  
{ _]yn"p  
oSavedFile = new RandomAccessFile(sName,"rw"); HIQ _%L4]  
this.nPos = nPos; 0KYEb%44  
oSavedFile.seek(nPos); nTuJEFn{  
} IAYR+c  
,-i zEr  
D&/kCi=R  
public synchronized int write(byte[] b,int nStart,int nLen) k,'L}SK  
{ 87Oad@FOr  
int n = -1; uZc`jNc\  
try{ G"\`r* O  
oSavedFile.write(b,nStart,nLen); #z&& M"*a|  
n = nLen; X*M#FT-  
} |kw)KEi}H  
catch(IOException e) U F?H>Y&  
{ iTFdN}U  
e.printStackTrace (); )0ea+ ib  
} (5#nrF]  
0*rQ3Z  
N03HQp)g  
return n; 2r!s*b\Ix  
} Zw*v  
)^ m%i]L _  
4#ug]X4Y')  
} 8)O[Aq::  
bu |a0h7e  
ERpnuMb  
/* hJn%mdx~w|  
**SiteInfoBean.java crqpV F]1]  
*/ V=zi >o`   
package NetFox; Y,W uBH  
"5-^l.CKH  
V^JV4 `o  
public class SiteInfoBean { N F2/B#q  
S'A>2>  
3{ LP?w:@  
private String sSiteURL; //Site's URL 1 y-y6q  
private String sFilePath; //Saved File's Path /4c\K-Z;  
private String sFileName; //Saved File's Name  Jd%H2`  
private int nSplitter; //Count of Splited Downloading File Fz1_w$^  
f#?fxUH~  
h!&prYx  
public SiteInfoBean() {U!8|(  
{//nSplitter的缺省值为5 wT `a3Ymm  
//default value of nSplitter is 5 Q7R~{5r>W  
this("","","",5); ZT,B(#m  
} T? tG~  
])L A42|  
'`eO\huf  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KMU4n-s"o  
{ I2 j}Am  
sSiteURL= sURL; 4G$|Rx[{,  
sFilePath = sPath; l7W 6qNB  
sFileName = sName; <1FC%f/  
this.nSplitter = nSpiltter; E0u~i59Z  
&GlwC%$S  
5!l0zLQP o  
} _{r=.W+ w  
@c<3b2  
LUuZ9$t0J"  
public String getSSiteURL() 6xWe=QGE  
{ ANJ$'3tg  
return sSiteURL; >iD )eB  
} : y5<go8e  
wW#}:59}  
Hj:r[/  
public void setSSiteURL(String value) oN{Z+T :  
{ I 4,K43|  
sSiteURL = value; 2C/$Ei^t  
} /h*>P:i].  
P^w#S  
Z2TL#@  
public String getSFilePath() kB'Fkqwm  
{ Eve.QAl|  
return sFilePath; mMb'@  
} "kMguK}c  
3H|_mX  
W6"v)Jc>_  
public void setSFilePath(String value) cgm81+[%r  
{ Fb7#<h  
sFilePath = value; SILQ  
} c3:,Ab|  
UVw~8o9s  
ag*mG*Z  
public String getSFileName() :cq9f2)  
{ 0TGLM#{  
return sFileName; ^1Zeb$Nw'  
} } p&&_?  
4W3\P9p=  
.a._NW  
public void setSFileName(String value) \RvvHty-V  
{ jFA{+Yr1  
sFileName = value; 7N:Y?Hi\  
} po$ /7  
O [i#9)  
xER\ZpA :,  
public int getNSplitter() rb1`UG"h$  
{ >TQH|}|6(y  
return nSplitter; +m8!U=Zi  
}  ))&;}2{  
m|=H#  
q{t*34R  
public void setNSplitter(int nCount) NX|v=  
{ ,`gl&iB  
nSplitter = nCount; d/ bEt&  
} mnmP<<8C,  
} =$nB/K,8AX  
H&]gOs3So  
yi l[gPy4B  
/* M#~Cc~oT  
**Utility.java w:?oTuw  
*/ :,J}z~I,lB  
package NetFox; XLL/4)  
|!"2fI  
Iz ;G*W18  
public class Utility { Yc,7tUz#  
O2BW6Wc  
91$]Qg,lB  
public Utility() %,Ap7X3:QT  
{ :{oZ~<  
~-PjW#J%  
df n9!h  
} Q8 DQlqHm  
;_^fk&+  
//线程睡眠 0#ClWynjRO  
public static void sleep(int nSecond) Eh|]i;G%  
{ G.( mp<-  
try{ |7X:TfJ  
Thread.sleep(nSecond); `;)\u  
} ik!..9aB  
catch(Exception e) " t7M3i_  
{ LxpuhvIO  
e.printStackTrace (); 7oq[38zB  
}  >lBD<;T  
} (HSgEs1d  
g_G6~-.9I  
//日志 x-?{E  
public static void log(String sMsg) nzmDA6d  
{  jcI&w#re  
System.err.println(sMsg); YhY:~  
} ds&e|VSH;  
]ut5S>,"  
$ZNu+tn Y  
public static void log(int sMsg) $dA-2e1 0  
{ 4"xPr[=iG  
System.err.println(sMsg); cCa|YW^j  
} NcP.;u;`  
} {; .T7dL  
2D:fJ~|-[  
S-YM%8A[  
/* |]aE<`D  
**TestMethod.java KyzFnVH3)  
*/ ~_s{0g]B  
package NetFox; HW7; {QMg  
*X4PM\ck  
jq+A-T}@  
public class TestMethod { $d,0=Ci  
lhtZaU~V  
c wOJy >  
public TestMethod() $*kxTiG!7  
{ ///xx/weblogic60b2_win.exe 6<$Odd  
try{ ND5`Q"k   
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1&P<  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Dgx8\~(E'  
SiteFileFetch fileFetch = new SiteFileFetch(bean); J]q%gcM  
fileFetch.start(); 8,atX+tc  
} #?XQ7Im  
catch(Exception e){e.printStackTrace ();} (XXheC  
P9S2?Q  
|QMhMGjV  
} V=lfl1Ev0J  
I8QjKI (  
l983vKr  
public static void main(String[] args) %/>Y/!;  
{ 9 JWa$iBH@  
new TestMethod(); Rcawc Y  
} JXw^/Y$  
} ~j-cS J3  
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
批量上传需要先选择文件,再选择上传
认证码:
验证问题:
10+5=?,请输入中文答案:十五