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http断点续传简单实现(java)

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/* *,|x p  
**SiteFileFetch.java K7X*N  
*/ [/o B jiBA  
package NetFox; 10Q!-K),p  
import java.io.*; @-Y,9mM   
import java.net.*; @REMl~"D5  
n1aOpz6`  
Al]*iw{  
public class SiteFileFetch extends Thread { `4?|yp.|L  
=f23lA  
R T~oJ~t;  
SiteInfoBean siteInfoBean = null; //文件信息Bean ZmycK:f  
long[] nStartPos; //开始位置 GvvKM=1  
long[] nEndPos; //结束位置 9-vQn/O^D  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 9Fw NX  
long nFileLength; //文件长度 So75h*e  
boolean bFirst = true; //是否第一次取文件 4?+jvVq  
boolean bStop = false; //停止标志 6!USSipn  
File tmpFile; //文件下载的临时信息 ^N7 C/" p  
DataOutputStream output; //输出到文件的输出流 B9Wd '  
.,U4 ATO  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Rlm28  
public SiteFileFetch(SiteInfoBean bean) throws IOException OF )*kiJ  
{ 7Ka4?@bQ  
siteInfoBean = bean; i2;,\FI@t%  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 'NCx<0*  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); F-M)6&T  
if(tmpFile.exists ()) e**'[3Y  
{ ;O 5Iu  
bFirst = false; dTlEEgR  
read_nPos(); CC'N"Xb  
} GU9p'E  
else @xso{$z?j  
{ D0MW~Y6{  
nStartPos = new long[bean.getNSplitter()]; wuXH'  
nEndPos = new long[bean.getNSplitter()]; %nE%^Enw  
} l8_RA  
* kUb[  
bxBndxl  
O'.{6H;t  
} oYJ<.Yxeb  
wAzaxeV=  
f 9IqcCSW  
public void run() osLEH?iKW  
{  p1&=D%/  
//获得文件长度 f'`y-]"V5)  
//分割文件 P=y1qqC  
//实例FileSplitterFetch U7,.L  
//启动FileSplitterFetch线程 |RqCI9N6  
//等待子线程返回 u09D`QPP]  
try{ N f}ZG  
if(bFirst) c`\qupnY  
{ bhfKhXh8  
nFileLength = getFileSize(); ,XN4Iy#BZl  
if(nFileLength == -1) B&EUvY '  
{ 5CH8;sMK  
System.err.println("File Length is not known!"); KmWd$Qy,  
} DV*e.Y>  
else if(nFileLength == -2) )U8=-_m  
{ Z]Cd>u  
System.err.println("File is not access!"); &F'n >QT9q  
} B@' OUcUR  
else A+fXt`YNM  
{ bJynUZ  
for(int i=0;i<nStartPos.length;i++) {T0Au{88H  
{ H5CL0#I  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); `84,R!  
} h66mzV:`  
for(int i=0;i<nEndPos.length-1;i++) \#C]|\  
{ 1>umf~%Wa  
nEndPos = nStartPos[i+1]; Q0g^%  
} }yd!UU  
nEndPos[nEndPos.length-1] = nFileLength; *-E'$  
} :edy(vC<  
} vu:] [2"0  
g]d0B!Ar~  
AH:0h X6+  
//启动子线程 9vCCE[9  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K.b :ae^k  
for(int i=0;i<nStartPos.length;i++) NC sem  
{ Sf2xI'  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [* |+ it+!  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .d?LRf  
nStartPos,nEndPos,i); TK0W=&6#A  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \Qf2:[-V0  
fileSplitterFetch.start(); bYr*rEcA  
} ZzxWKIE'c  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h-DHIk3/  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {vQ:4O!:  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s&XL{FE  
nEndPos = " + nFileLength); `v)ZOw9&  
// fileSplitterFetch[nPos.length-1].start(); `^|l+TJG  
U/_hH*N"!  
jsP+,brO  
//等待子线程结束 5kojh _\  
//int count = 0; i1*0'x  
//是否结束while循环 yJ ;Qe_up  
boolean breakWhile = false; oN`khS]_v0  
IR8yE`(h  
R iFUa $  
while(!bStop) }'K-1:  
{ I1I-,~hO  
write_nPos(); gEw9<Y  
Utility.sleep(500); 9!.S9[[N  
breakWhile = true; 6:6A" A  
K=nDC.  
YbnXAi\y|  
for(int i=0;i<nStartPos.length;i++) 'W>y v  
{ ';c 6  
if(!fileSplitterFetch.bDownOver) $mE3 FJP>  
{ '$EyVu!  
breakWhile = false; E`<ou_0N@q  
break; }6<5mq)%  
} 4*Gv0#dga  
} kS=nH9  
if(breakWhile) Zq<j}vVJ  
break; URg;e M#  
VZ =:`)  
`JpFqZ'58  
//count++; nE*S3  
//if(count>4) LExm#T`  
// siteStop(); EP>Lh7E9n  
}  ;<B  
Q"nw.FjUG  
OFyy!r@?  
System.err.println("文件下载结束!"); lS7L|  
} cNxxX!P/  
catch(Exception e){e.printStackTrace ();} U5H%wA['m  
} njg0MZBqA  
C$~ly=@  
3en6 7l  
//获得文件长度 d~%7A5  
public long getFileSize() #)xlBq4cZ  
{ `'<$N<!  
int nFileLength = -1; > !s<JKhI  
try{ r(uo-/7z  
URL url = new URL(siteInfoBean.getSSiteURL()); EFh^C.S8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;hO6 p  
httpConnection.setRequestProperty("User-Agent","NetFox"); + c3pe4  
cl `Wl/Q#  
d]O:VghY\  
int responseCode=httpConnection.getResponseCode(); U\:Y*Ai  
if(responseCode>=400) .x,y[/[[)  
{ {TpbUj0  
processErrorCode(responseCode); R@jMFh;  
return -2; //-2 represent access is error SF+L-R<e  
} nCWoco.xy  
gFHBIN;u  
hIV]ZYbH  
String sHeader; \L~^c1s3r  
>\<eR]12  
Oj_]`  
for(int i=1;;i++) bS~Y_]B  
{ a<\n$E#q  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p:y\{k"  
//Utility.log(in.readLine()); QR"+fzOL  
sHeader=httpConnection.getHeaderFieldKey(i); l9Ol|Cb&  
if(sHeader!=null) oJQS&3;/r  
{ /"D,gn1S*  
if(sHeader.equals("Content-Length")) H i8V=+  
{ &-Ch>:[  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [>a3` 0M  
break; PbZ%[F  
} Bc }o3oc  
} uCB9;+ Hjw  
else qCcLd7`$  
break; >YWK"~|i~  
} )4B`U(%M~  
} .tG3g:  
catch(IOException e){e.printStackTrace ();} [q!]Ds" _  
catch(Exception e){e.printStackTrace ();} -~8PI2  
F*J1w|)F0  
Yl&[_ l  
Utility.log(nFileLength); q:)PfP+  
RN)XIf$@_  
MnFrQC  
return nFileLength; QnS^ G{  
} JW0\y+o~  
bR"4:b>K  
Z ;rM@x  
//保存下载信息(文件指针位置) e< @$(w  
private void write_nPos() 98u@X:3  
{ ${z#{c1  
try{ MMKN^a"GA  
output = new DataOutputStream(new FileOutputStream(tmpFile)); kBA.N l7  
output.writeInt(nStartPos.length); DjK7_'7(L  
for(int i=0;i<nStartPos.length;i++) L3oL>r'|  
{ >2>/ q?  
// output.writeLong(nPos); h@O\j&#  
output.writeLong(fileSplitterFetch.nStartPos);  YC 6guy>  
output.writeLong(fileSplitterFetch.nEndPos);  tM\BO0  
} w?u3e+  
output.close(); s'N<  
} [! ;sp~  
catch(IOException e){e.printStackTrace ();} N}nE9z5  
catch(Exception e){e.printStackTrace ();} BJ3<"D{.*4  
} -?#iPvk6  
36co 'a4,  
iTdamu`L  
//读取保存的下载信息(文件指针位置)  ]XlBV-@b  
private void read_nPos() ,OwTi:yDr  
{ >G!=lLyR  
try{ 0OG 3#pE  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 71E~~$  
int nCount = input.readInt(); a(yWIgD\\  
nStartPos = new long[nCount]; ua=7YG  
nEndPos = new long[nCount]; q0ab]g+  
for(int i=0;i<nStartPos.length;i++) X6B,Mply  
{ p3-~cr.LD  
nStartPos = input.readLong(); 0 5?`W&:9  
nEndPos = input.readLong(); eV(.\Lj  
} $$p +~X  
input.close(); p)Q5fh0-  
} fO5L[U^`  
catch(IOException e){e.printStackTrace ();} 5ad@}7&  
catch(Exception e){e.printStackTrace ();} *uK!w(;2  
} -0;{  
%LHt{:9.  
dj] O  
private void processErrorCode(int nErrorCode) >\'}&oi  
{  nXy"  
System.err.println("Error Code : " + nErrorCode); rVOF  
} 9_svtO]P  
[-W~o.`  
s H'FqV,)  
//停止文件下载 IAb.Z+ig  
public void siteStop() O['[_1n_u]  
{ oMM@{Jp  
bStop = true; JY:Fu  
for(int i=0;i<nStartPos.length;i++) ZV5IZ&V!  
fileSplitterFetch.splitterStop(); ESIeZhXVH  
X H!n{Of  
:*l\j"fX5  
} X?r$o>db  
} Bbb":c6w0  
//负责部分文件的抓取 K`|V1L.m  
**FileSplitterFetch.java _-v$fDrz  
*/ H-m).^  
package NetFox; 4w 7vgB  
`'(@"-L:7  
H\<PGC"_Y  
import java.io.*; u!VrMH  
import java.net.*; r24 s_  
ay{]Vqi9  
8y?q)y9h  
public class FileSplitterFetch extends Thread { >k}Kf1I  
tM:$H6m/(  
dleLX%P  
String sURL; //File URL 7{rRQ~s&g9  
long nStartPos; //File Snippet Start Position %~Ymb&ugg  
long nEndPos; //File Snippet End Position q*K.e5"'  
int nThreadID; //Thread's ID B3&`/{u  
boolean bDownOver = false; //Downing is over Ha20g/ UN.  
boolean bStop = false; //Stop identical ^e WD4Vp|4  
FileAccessI fileAccessI = null; //File Access interface l=t$ XWh!  
\@:mq]Y  
3R$*G8v  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W&0KO-}ot  
{ !5[5l!{x  
this.sURL = sURL; 2z0 27P-Q  
this.nStartPos = nStart; EEO)b_(  
this.nEndPos = nEnd; U>kL|X3 V  
nThreadID = id; *`wgqin  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A;C)#Q/  
} $ #F7C[2N  
7 a_99? J  
\TXCq@  
public void run() #R3|nL  
{ 5Qgh\4  
while(nStartPos < nEndPos && !bStop) =LMM]'no,  
{ 97L# 3L6t  
ygfUy  
R8<P}mv  
try{ "94qBGf  
URL url = new URL(sURL); "iTi+UZxe  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jr=erVHK  
httpConnection.setRequestProperty("User-Agent","NetFox"); f 8836<c  
String sProperty = "bytes="+nStartPos+"-"; @t?uhT*Z=  
httpConnection.setRequestProperty("RANGE",sProperty); O0 ,=@nw8.  
Utility.log(sProperty); H)l7:a  
I Z{DR  
l^E)XWd  
InputStream input = httpConnection.getInputStream(); GbN|!,X1m  
//logResponseHead(httpConnection); YB'BAX<lI  
xnD"LK  
2uM\?*T@  
byte[] b = new byte[1024]; L4-v'Z;  
int nRead; :LEC[</yvl  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) As-xO~+  
{ C;NG#4;'  
nStartPos += fileAccessI.write(b,0,nRead); -7:_Dy  
//if(nThreadID == 1) (S1Co&SX  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1=Nh<FuQ  
} ct![eWsuB  
~zT743  
b;%>?U`>p  
Utility.log("Thread " + nThreadID + " is over!"); :927y  
bDownOver = true; tDIQ=  
//nPos = fileAccessI.write (b,0,nRead); zyi;vu  
} MGE8S$Z  
catch(Exception e){e.printStackTrace ();} QNe siV0MI  
} .-HwT3  
} - HiRXB  
8Xjp5  
2\J-7o=P  
//打印回应的头信息 $|%BaEyk  
public void logResponseHead(HttpURLConnection con) r>ca17  
{ -oR P ZtW  
for(int i=1;;i++) R /0zB  
{ ZF~@a+o  
String header=con.getHeaderFieldKey(i); *'jI>^o  
if(header!=null) 5VR=D\j  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qz6@'1  
Utility.log(header+" : "+con.getHeaderField(header)); K#!c<Li#  
else .bvEE  
break; dcbE<W#ss  
} &Y3 r'"  
} OT{cP3;0*o  
!ZrU@T  
R7ze~[oF  
public void splitterStop() J_rb3  
{ I$HO[Z!  
bStop = true; g?i0WS  
} @K=C`N_22  
GZWU=TC2{2  
GW;O35 m  
} #4BwYj(Sl  
GLtd6;V  
SA[wF c  
/* iw\yVd^]:k  
**FileAccess.java &.1qixXIr  
*//文件访问(定位,写) vMYL( ]e  
package NetFox; 5VZZk%oy  
import java.io.*; 5DxNHEuS  
13K|=6si  
4U>g0  
public class FileAccessI implements Serializable{ 51-@4E2:l:  
kr>4%Ndm7  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 92XG|CWX  
RandomAccessFile oSavedFile; oFL7dL  
long nPos; Gw-y6e'|Y  
T7R,6 qt  
r%\%tz'`j  
public FileAccessI() throws IOException %i5tf;x6i  
{ '@dk3:3t  
this("",0); >yf}9Zs  
} ~`X$b F  
g$ h`.Fk,  
N.UeuLz  
public FileAccessI(String sName,long nPos) throws IOException ,xI FF-[0  
{ W:8pmI  
oSavedFile = new RandomAccessFile(sName,"rw"); Kw=][}d`D  
this.nPos = nPos; )}lO%B'K  
oSavedFile.seek(nPos); u5N&Wn{  
} lsA?|4`mn  
-BcnJK0  
{R8)DK  
public synchronized int write(byte[] b,int nStart,int nLen) sZPyEIXie  
{ 9%Qlg4~<s  
int n = -1; V `7(75  
try{ OF/hD2V  
oSavedFile.write(b,nStart,nLen); 2@,rIve  
n = nLen; 3HqTVq`&  
} pv8vW'G\E  
catch(IOException e) 8_/,`}9   
{ @Nn'G{8OG  
e.printStackTrace (); L<k(stx~  
} RA1K$D ?A  
V 5D8z  
c2Wp 8l  
return n; MSE0z !t  
} &} r-C97  
qs {wrem  
3b[.s9Q  
} K_F"j!0  
GIhX2EvAS  
5Nl?Km~  
/* <w3_EO  
**SiteInfoBean.java !v. <H]s)  
*/ gH yJ~  
package NetFox; [ji')PCAi;  
 kMZo7 y  
I%l2_hs0V  
public class SiteInfoBean { x>tsI}C  
@%jY  
c 5 `74g  
private String sSiteURL; //Site's URL U".5x~UC  
private String sFilePath; //Saved File's Path upnX7as  
private String sFileName; //Saved File's Name 9[R+m3V/`  
private int nSplitter; //Count of Splited Downloading File +GncQs y  
p z\8Bp}yo  
Q^*4FH!W  
public SiteInfoBean() Irui{%T  
{//nSplitter的缺省值为5 1`GW>ZKv  
//default value of nSplitter is 5 KW!+Ws  
this("","","",5); >X xHp  
} X?o6=)SC|  
T: SqENV  
E24j(>   
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) re4A5Ev$  
{ 8jY<S+[o  
sSiteURL= sURL; aNBwb9X  
sFilePath = sPath; |K" nSXzk  
sFileName = sName; 0BH-kr  
this.nSplitter = nSpiltter; ZW4$Ks2]Y  
Hb/8X !=  
D#A6s32a  
} 1Tr%lO5?6  
U>sEFzBup  
gJ~CD1`O  
public String getSSiteURL() -@ra~li,yQ  
{ h_]*|[g  
return sSiteURL; Ckc5;:b&m  
} yb,X }"Et  
vR&b2G7o  
[=",R&uD$  
public void setSSiteURL(String value) `Tei  
{ C80< L5\  
sSiteURL = value; b +Z/nfS  
} Ahc9HA2  
;2$0j1>  
5WvsS( 9H  
public String getSFilePath() )7p(htCz5  
{ ^#IE t#  
return sFilePath; Wt=\hixj-  
} Z1Qv>@u  
K>C@oE[W  
0Y:)$h2?  
public void setSFilePath(String value) $ w+.-Tr  
{ =sAU5Ag68  
sFilePath = value; Z*ag{N  
} r`\@Fv,&#  
v^)B [e!  
mZM,"Wq,  
public String getSFileName() CI-1>= "OE  
{ ahQY-%>  
return sFileName; 4j8$& ~/  
} r Nurzag  
#d06wYz=  
_8!x  
public void setSFileName(String value) v*&j A 8D  
{ u:Ye`]~o  
sFileName = value; m'N8[ o|h  
} evpy%/D  
jgS3#  
ANJL8t-m  
public int getNSplitter() tfu`_6  
{ ! ,{zDMA  
return nSplitter; P]TT8Jgw  
} {9X mFa  
vCNq2l^CW  
#6v357-5  
public void setNSplitter(int nCount) ^d@2Y0hH  
{ bt(Y@3;  
nSplitter = nCount; )EQz9  
} v~yw-}fk%  
} H^54o$5  
KVh#"]<WV  
1)jea wVmj  
/* `SOQPAnK+;  
**Utility.java RRpY%-8M  
*/ \yZVn6GVr  
package NetFox; i7Cuc+ j8  
_C (fz CK  
{}rnn$HQe  
public class Utility { 5Zd oem  
FJ4,|x3v[x  
a+\<2NXYD  
public Utility() D9NQ3[R 9  
{ 5gII|8>rQ  
jvAjnh#  
\*'@F+  
} Kn<+Au_]L  
Z4c'1-lh  
//线程睡眠 /qMnIo  
public static void sleep(int nSecond) y:^o ._  
{ /]_|uN)Q  
try{ j"hEs(t  
Thread.sleep(nSecond); &3;"$P  
} D~BL Txq  
catch(Exception e) g4W/T  
{ H(tC4'tA  
e.printStackTrace (); D[?;+g/  
} !icI Rqcf=  
} .@%L8_sMR  
v|\#wrCT?  
//日志 |cP:1CRzi  
public static void log(String sMsg) \HkBp& bqK  
{ l qwy5#  
System.err.println(sMsg); l2:-).7xt  
} 3;VH'hh_  
%p$XK(6  
vd(S&&]o1  
public static void log(int sMsg) _p5#`-%mM  
{ >j3':>\U  
System.err.println(sMsg); 7}y@VO6]  
} 6wj o:I  
} u$C\#y7  
F[SZwMf29  
Maq`Or|4  
/* L+p}%!g  
**TestMethod.java Q{?\qCrrYl  
*/ dNNXMQ0"  
package NetFox; m;\nMdn  
jf`w8*R  
=}kISh  
public class TestMethod { mXyN{`q=  
U;4i&=.!  
[DDe}D3C  
public TestMethod() /RMtCa~  
{ ///xx/weblogic60b2_win.exe @'):rFr@F  
try{ U~)5{  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); az:}RE3o  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pe0ax- Zv  
SiteFileFetch fileFetch = new SiteFileFetch(bean); }/&Zo=Q$  
fileFetch.start(); :$k1I-^R  
} =0] K(p,  
catch(Exception e){e.printStackTrace ();} m$^5{qpg  
.?5 ~zK  
f S/:OnH  
} M>Tg$^lm  
}2LWDQ;po  
% &&)[  
public static void main(String[] args) /g!ZU2&l  
{ K>e-IxA);0  
new TestMethod(); >6jal?4u-  
} V^R,j1*  
} " "m-5PGYo  
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