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
  • 8292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
/* se S)`@n  
**SiteFileFetch.java ? oQ_qleuo  
*/ C<E;f]d  
package NetFox; tD+K4 ^  
import java.io.*; nC@UK{tVa  
import java.net.*; U&OE*dq  
P~@.(hed  
IJ2>\bW_p  
public class SiteFileFetch extends Thread { K {__rO  
l.%[s6  
/9<62F@zJ"  
SiteInfoBean siteInfoBean = null; //文件信息Bean 2 X`5YN;  
long[] nStartPos; //开始位置 mApl}I  
long[] nEndPos; //结束位置 m<GJ1)%3i  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 sSsRn*LN-:  
long nFileLength; //文件长度 QvDD   
boolean bFirst = true; //是否第一次取文件 B'-L-]\H  
boolean bStop = false; //停止标志 oF=UjA  
File tmpFile; //文件下载的临时信息 lk%W2N5  
DataOutputStream output; //输出到文件的输出流 1J[|Ow  
Z:Nm9m  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) >OW>^%\!1  
public SiteFileFetch(SiteInfoBean bean) throws IOException "dFuQB  
{ ?gl[ =N V  
siteInfoBean = bean; O_|p{65  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); k%h%mz  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); t_{rKb,  
if(tmpFile.exists ()) "V:E BR  
{ H<C+ rAIb  
bFirst = false; %z5P%F'5   
read_nPos(); RtScv  
} =7 ${bp!  
else YY9Ub  
{ A"no!AN  
nStartPos = new long[bean.getNSplitter()]; O K2|/y  
nEndPos = new long[bean.getNSplitter()]; U=>4=gsG  
} cP &XkAQ  
kz?m `~1  
VQ'DNv| 9  
`'}c- Q  
} W6L}T,epX  
^laf!kIP  
d ~3G EK  
public void run() M$+2f.(>k)  
{ s5D<c'-  
//获得文件长度 ma7@vD  
//分割文件 wwh)B92Y5  
//实例FileSplitterFetch @Sd l~'"  
//启动FileSplitterFetch线程 ey! {  
//等待子线程返回 iTg7@%  
try{ &s<'fSI  
if(bFirst) nN[gAM (  
{ -3eHJccB  
nFileLength = getFileSize(); q+}Er*r  
if(nFileLength == -1) v %GcNjZk5  
{ oCR-KR>{Q  
System.err.println("File Length is not known!"); g xf|L>=  
} YMTB4|{  
else if(nFileLength == -2) d vTsbs/6  
{ 4> $weu^  
System.err.println("File is not access!"); {rWFgn4Li  
} kG70j{gf  
else PTFe>~vr*  
{ +\@WOs  
for(int i=0;i<nStartPos.length;i++)  cnwpd%]o  
{ )3RbD#?  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); }ikJ a  
} F^)SQ%xx  
for(int i=0;i<nEndPos.length-1;i++) 1X$hwkof  
{ 2E d  
nEndPos = nStartPos[i+1]; c<n <!!vi  
} {9yW8&m  
nEndPos[nEndPos.length-1] = nFileLength; #}U*gVYe  
} c<J/I_!  
} FZW:dsm  
g4fe(.?c,  
f}U@e0Lsb  
//启动子线程 }9,^=g-  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z UCz-53  
for(int i=0;i<nStartPos.length;i++)  >!7\Rx  
{ -F+dmI,1$  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qqR8E&Y{  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [#hoW"'Q9  
nStartPos,nEndPos,i); t)hAD_sf  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 95%, 8t  
fileSplitterFetch.start(); si|DxDx  
} $7bl,~Z  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), js#72T/_n  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z(=U ZI?  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zjVQ\L  
nEndPos = " + nFileLength); |-SImxV  
// fileSplitterFetch[nPos.length-1].start(); L[s8`0  
|#6))Dh  
I/ q>c2Pw$  
//等待子线程结束 u:FFZ  
//int count = 0; 0nbQKoF  
//是否结束while循环 LAT%k2%Wx  
boolean breakWhile = false; jQc.@^#+x  
&bO5+[  
@h&crI[c  
while(!bStop) 9gLUM$Kd  
{ DfJHH)Ry}  
write_nPos(); w6 x{ <d  
Utility.sleep(500); :Vyr8+]  
breakWhile = true; ;F:~HrxT}  
keYvscRBI  
)GpH5N'EI  
for(int i=0;i<nStartPos.length;i++) U=a'(fX  
{ zAxscD f'  
if(!fileSplitterFetch.bDownOver) ]$VYzE2e  
{ b+g(=z+  
breakWhile = false; x/pM.NZF1  
break; v_$'!i$  
} .%'$3=/oe  
} |QI FtdU5T  
if(breakWhile) wf= s-C  
break; fuQb h  
N4wv'OrL]  
<e s>FD  
//count++; BV8-\R@  
//if(count>4) Z?#_3h$"T  
// siteStop(); )TmqE<[  
} S-8wL%r  
opKk#40  
.=nx5y z  
System.err.println("文件下载结束!"); .[ E"Kb}=  
} k[6xuyY]  
catch(Exception e){e.printStackTrace ();} H)Zb_>iV  
} soH M5<U  
9<9 c^2  
Dj~]]  
//获得文件长度 99\;jz7  
public long getFileSize() TaZw_)4c  
{ h#o3qY  
int nFileLength = -1; .!kO2/:6  
try{ `o.DuvQ E  
URL url = new URL(siteInfoBean.getSSiteURL()); U8T"ABvFP  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >z`^Q[  
httpConnection.setRequestProperty("User-Agent","NetFox"); WCg*TL}  
P?y3YxS  
~1NK@=7T  
int responseCode=httpConnection.getResponseCode(); *6-fvqCv  
if(responseCode>=400) b&y"[1`  
{ J< E"ZoY  
processErrorCode(responseCode); C;T:'Uws  
return -2; //-2 represent access is error nj (/It  
} *q?-M"K  
|HjoaN)  
=9lrPQ]w  
String sHeader; 3c"$@W:>  
5&y;r  
PjH[8:,  
for(int i=1;;i++) fjE  
{ 3 e19l!B  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >d`XR"_e  
//Utility.log(in.readLine()); $Vi[195]2  
sHeader=httpConnection.getHeaderFieldKey(i); sg.8Sd"]7  
if(sHeader!=null) 8$|< `:~J  
{ e~#"#?  
if(sHeader.equals("Content-Length")) %~V+wqu  
{ >t[beRcR6  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g1je':  
break; ]%{.zl!  
} PY4RwN  
} WcCJ;z:S?k  
else r((2.,\Z  
break; 6I$laHx?  
} {*=+g>R gD  
} M~0A-*N  
catch(IOException e){e.printStackTrace ();} j.3#rxq  
catch(Exception e){e.printStackTrace ();} *H"IW0I  
ArFsr  
~*3obZ2>2  
Utility.log(nFileLength); fp jy[$8  
&=1A g}l57  
0 !D,74r  
return nFileLength; h>'9-j6B  
} A@8Ot-t:\2  
&C~R*  
y:U'3G-  
//保存下载信息(文件指针位置) LQ,RQ~!  
private void write_nPos() thoAEG80  
{ jV(\]g"/=  
try{ DCJmk6p%0  
output = new DataOutputStream(new FileOutputStream(tmpFile)); _RLx;Tn)L  
output.writeInt(nStartPos.length); ugtzF  
for(int i=0;i<nStartPos.length;i++) 2Xu?/yd  
{ ? m$uqi  
// output.writeLong(nPos); O*hd@2hd  
output.writeLong(fileSplitterFetch.nStartPos); e&Z\hZBb  
output.writeLong(fileSplitterFetch.nEndPos); zW`Zmt\T2  
} =h?Q.vad  
output.close(); R&w2y$  
}  0p8Z l  
catch(IOException e){e.printStackTrace ();} "6T: &>  
catch(Exception e){e.printStackTrace ();} *WSH-*0  
} T6X%.tR>`  
 R^%uEP  
'~dE0ohWb  
//读取保存的下载信息(文件指针位置) UbBo#(TZ)  
private void read_nPos() Bg^k~NX%  
{ fI{ZElPp  
try{ x^UE4$oo  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #n=b*.  
int nCount = input.readInt(); KY)r kfo B  
nStartPos = new long[nCount]; ?e? mg  
nEndPos = new long[nCount]; / 38b:,  
for(int i=0;i<nStartPos.length;i++) 8>: kv:MId  
{ 3pxm0|  
nStartPos = input.readLong(); =1dU~B:Lm  
nEndPos = input.readLong(); traJub  
} +O< 0q"E  
input.close(); /Q7cQ2[EU  
} 9N H"Ik*  
catch(IOException e){e.printStackTrace ();} KFCL|9P  
catch(Exception e){e.printStackTrace ();} S ("Zzq`  
} +/A`\9QT  
+k!Y]_&(:f  
RB5fn+FiZ  
private void processErrorCode(int nErrorCode) jB8n\8 Bs  
{ )I80Nq  
System.err.println("Error Code : " + nErrorCode); Ua.7_Em  
} FHNK%Ko  
>Z#=<  
` [ EzU+  
//停止文件下载 32_{nLV$[  
public void siteStop() xl%!7?G|$>  
{ )7mX]@  
bStop = true; O*3x'I*a  
for(int i=0;i<nStartPos.length;i++) 20hF2V  
fileSplitterFetch.splitterStop(); 1'5I]D ec  
`{g8A P3  
Gt&x<  
} K\ww,S  
} "ei*iUBN:  
//负责部分文件的抓取 +):t6oX|  
**FileSplitterFetch.java <!.'"*2  
*/ J@ x%TA  
package NetFox; R5LzqT,/N:  
*|n::9  
nZ>bOP+,  
import java.io.*; gY AXUM,  
import java.net.*; %?^T^P  
~Mv@Bl  
,63hO.4M  
public class FileSplitterFetch extends Thread { Wxl^f?I`:  
NiU}A$U  
.O [RE_j  
String sURL; //File URL q<>  
long nStartPos; //File Snippet Start Position u,0N[.&N  
long nEndPos; //File Snippet End Position F]~rA! g1  
int nThreadID; //Thread's ID !dfc1UjB  
boolean bDownOver = false; //Downing is over -If-c'"G  
boolean bStop = false; //Stop identical  `"v5bk  
FileAccessI fileAccessI = null; //File Access interface N=K|Nw  
*F+t`<2  
66<3zadJZU  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qu[ ~#  
{ dzZ74FE!t  
this.sURL = sURL; o+W5xHe^1  
this.nStartPos = nStart; ]trVlmZXH}  
this.nEndPos = nEnd; 4l2i'H  
nThreadID = id; 3X$)cZQ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @ NGK2J  
} 8~?3: IZ  
kVs'>H@FY  
<}b`2/wP  
public void run() ;crQ7}k  
{ ryzz!0l  
while(nStartPos < nEndPos && !bStop) I0 a,mO;m  
{ 5EDN 9?a  
X3#/|>  
*6~ODiB  
try{ TEl :;4  
URL url = new URL(sURL); LRBcW;.Su  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pN/)$6=  
httpConnection.setRequestProperty("User-Agent","NetFox"); R6~x!  
String sProperty = "bytes="+nStartPos+"-"; !=@Lyt)_b  
httpConnection.setRequestProperty("RANGE",sProperty); O(;K ]8  
Utility.log(sProperty); m "\jEfjO  
z]ZhvH7-  
7''l\3mIn  
InputStream input = httpConnection.getInputStream(); 6Y6DkFdvrZ  
//logResponseHead(httpConnection); iph>"b$D  
v5l)T}Nb  
%pgie"k   
byte[] b = new byte[1024]; tVd\r"0k  
int nRead; pfgFHNH:  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R*IO%9O  
{ 7P O3{I  
nStartPos += fileAccessI.write(b,0,nRead);  5<bc>A-  
//if(nThreadID == 1) |cStN[97%  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |;_NCy8i3X  
} #k8bZ?*:  
<qN0Q7  
V{;!vt~  
Utility.log("Thread " + nThreadID + " is over!"); {]<l|qK  
bDownOver = true; 8*3o 9$Pj  
//nPos = fileAccessI.write (b,0,nRead); !Uz{dFJf;  
} \bqIe}3V7  
catch(Exception e){e.printStackTrace ();} 0F-X.Dq  
} %"PG/avo  
} lxy_O0n  
D'Tb=  
n"8vlNeW  
//打印回应的头信息 l CHaRR7  
public void logResponseHead(HttpURLConnection con) k@U8K(:x  
{ x@I*(I  
for(int i=1;;i++) jZeY^T)f"  
{ ~4h<nc  
String header=con.getHeaderFieldKey(i); Nq1la8oQ3  
if(header!=null) fyPpzA0  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3Yf&F([t  
Utility.log(header+" : "+con.getHeaderField(header)); ^%|,G:r  
else GZ0? C2\  
break; ]|62l+  
} 1ael{b!  
} 1>P[3Y@}  
_#@n^c  
b/'{6zn  
public void splitterStop() lo*OmAF  
{ k8H@0p  
bStop = true; WV&T   
} D/)wg$MI  
,T@+QXh  
)9F-h8 &"  
} VZo[\sWf  
1BT]_ cP  
HA&7 ybl  
/* +\g/KbV7  
**FileAccess.java {T4F0fu[eR  
*//文件访问(定位,写) }a?PB o`  
package NetFox; F: %-x=q  
import java.io.*; A>WMPe:sSS  
i ,Cvnp6Lv  
j8n_:;i*  
public class FileAccessI implements Serializable{ s}Phw2`1U  
Py*( %  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2N*XzVplN  
RandomAccessFile oSavedFile; .nN=M>#/  
long nPos; )!6JSMS  
n%'M?o]DF  
2gM=vaiH=  
public FileAccessI() throws IOException V]I@&*O~ r  
{ ,/0Q($oz  
this("",0); <xM$^r)  
} LXYpP- E  
yg({g "  
<Sds5 d  
public FileAccessI(String sName,long nPos) throws IOException U%%fKL=S  
{ 9/A$ 3#wF  
oSavedFile = new RandomAccessFile(sName,"rw"); l{b<rUh5W  
this.nPos = nPos; 1ocd$)B|}  
oSavedFile.seek(nPos); Q{%2Npvq  
} 1 & G0;  
8Aq [@i  
FY;\1bt<<  
public synchronized int write(byte[] b,int nStart,int nLen) k3[rO}>s  
{ V~#e%&73FH  
int n = -1; xPBSJhla  
try{ /$NDH]a  
oSavedFile.write(b,nStart,nLen); $ti*I;)h4  
n = nLen; rP4v_?Zg+  
} =^liong0  
catch(IOException e) $DPMi9,7^  
{ +'fy%/  
e.printStackTrace (); ^RL#(O  
} UI:YzR  
9Z?P/ o  
.'`7JU#{  
return n; HCBZ*Z-  
} x"g-okLN  
v[$-)vs*ag  
(<M^C>pldf  
} %>,B1nt  
'u9,L FO  
@8keLrp  
/* E`E$ }iLs  
**SiteInfoBean.java Q1ox<-  
*/ 1Yr&E_5/  
package NetFox; m(2(Caz{  
0[A4k:  
QuF76&)7  
public class SiteInfoBean { L >* F8|g  
4Cd#S9<ed  
!v/j*'L<M}  
private String sSiteURL; //Site's URL ^pI&f{q  
private String sFilePath; //Saved File's Path i 4sd29v  
private String sFileName; //Saved File's Name O &/9wi>!q  
private int nSplitter; //Count of Splited Downloading File =1!,A  
0<g;g%   
CsJ38]=Mt  
public SiteInfoBean() N 3M:|D  
{//nSplitter的缺省值为5 24Y8n  
//default value of nSplitter is 5 /5x~3~  
this("","","",5); @ve4rc/LI  
} n jfh4}g:  
}"$2F0  
C(=$0FIR  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g&79?h4UXQ  
{ q+j.)e  
sSiteURL= sURL; ywSV4ZtM  
sFilePath = sPath; y15 MWZ  
sFileName = sName; 0n FEPMO  
this.nSplitter = nSpiltter; =)h<" 2  
8LI aN}  
;8| D4+  
} rL kUIG  
?MW *`U  
mYU7b8x_  
public String getSSiteURL() 5hhiP2q  
{ S1Z~-i*w  
return sSiteURL; Dw%V.J/&o  
} >AtW  
z;c~(o@4  
*Ce8( "v,  
public void setSSiteURL(String value) oVD)Fb%[i9  
{ fbl8:c)I  
sSiteURL = value; J|O=w(  
} N5ph70#y3  
[N35.O6P6u  
A#b`{C~l  
public String getSFilePath() k$ ya.b<X/  
{ wgN)*dpuI  
return sFilePath; (f-Mm0%[  
} *A^j>lV  
wqB 5KxO  
vb&1 S  
public void setSFilePath(String value) zeC@!,lH  
{ &J]|pf3m  
sFilePath = value; 1X ?9Ji)h  
} T>~D(4r|pS  
~o <+tL  
k=nN#SMn  
public String getSFileName() u{asKUce\  
{ JU6PBY~C'  
return sFileName; ,qj1"e  
} Y=NXfTc  
I^u$H&  
!ek};~(  
public void setSFileName(String value) $i|c6&  
{ &7fwYV  
sFileName = value; i[+cNJ|$B0  
} x5X;^.1Fr  
$ ]fautQlt  
nEG+TRZ)\  
public int getNSplitter() oP"X-I  
{ pv}k=wqJ1  
return nSplitter; 5z T~/6-(  
} SU` RHAo  
,Ky-3p>  
I7S#vIMXR.  
public void setNSplitter(int nCount) 8V08>M  
{ ^D}]7y|fm  
nSplitter = nCount; cn3F3@_"\  
} .{=|N8*py8  
} [9lfR5=Xw[  
2w7PwNb*32  
hoDE*>i  
/* wnPg).  
**Utility.java `\pv^#5HV9  
*/ O:I"<w9_1  
package NetFox; ; 1^ ([>|  
nZtP!^#  
zxo" +j4Ym  
public class Utility { XMLJ X~  
8M~^/Zc  
hi.` O+;  
public Utility() $ Ith8p~  
{ L3@upb  
d41DcgG'j(  
HT% =o}y  
} Pw :{  
!#[=,'Y  
//线程睡眠 w y\0o  
public static void sleep(int nSecond) &hSABtr}  
{ PL}c1Ud  
try{ C-:lM1  
Thread.sleep(nSecond); `p'(:W3a  
} gR]NH  
catch(Exception e) jI;iTKjB(  
{ d siQ~ [   
e.printStackTrace (); e*Gt%'  
} d OYEl<!J  
} ]E:K8E  
y+"6Y14  
//日志 {~y,.[Ga  
public static void log(String sMsg) ?r}'0dW  
{ >Hd0l L  
System.err.println(sMsg); h't! 1u  
} Y;uQq-CP  
f7y3BWOi]  
p3q >a<  
public static void log(int sMsg) c*~ /`lG  
{ Pf/_lBtL  
System.err.println(sMsg); >69-[#P!  
} D00v"yp%%  
} #JD:i%  
Q/2(qD; u  
"pa2,-&  
/* 1I#]OY#>  
**TestMethod.java Fo:60)Lr  
*/ m(0c|-  
package NetFox; d>wpG^"w  
QrSF1y'd  
a^xt9o`  
public class TestMethod { Kwmtt  
.VG5 / 6zp  
N\nxo0sl  
public TestMethod() T4fVZd)x  
{ ///xx/weblogic60b2_win.exe n8RE  
try{ ZdsYIRU#  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /9o gg  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y A:!ULzR*  
SiteFileFetch fileFetch = new SiteFileFetch(bean); N, SbJ Z  
fileFetch.start(); Pz77\DpFi  
} +v{g'  
catch(Exception e){e.printStackTrace ();} s)BB(vQ]6  
:oeDksld  
ui .riD[,O  
} ?? 2x*l1  
;QS(`SK l  
PO@b9O  
public static void main(String[] args) !+H)N  
{ `iZ){JfAH  
new TestMethod(); sogdM{tz\  
} 7 /7,55  
} 'Z}3XVZEN  
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:
3+5=?,请输入中文答案:八 正确答案:八