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http断点续传简单实现(java)

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/* P0@,fd<  
**SiteFileFetch.java DQ3<$0  
*/ 8LKiS  
package NetFox; 8tL~FiHb"  
import java.io.*; N7"W{"3D  
import java.net.*; L0,'mS  
2G7Wi!J  
3`g^  
public class SiteFileFetch extends Thread { b}`T Ln  
[JiH\+XLPs  
f|5co>Hk  
SiteInfoBean siteInfoBean = null; //文件信息Bean 7.Op<  
long[] nStartPos; //开始位置  ?9/G[[(  
long[] nEndPos; //结束位置 sRs>"zAg  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 dV_G1'  
long nFileLength; //文件长度 i5Ggf"![  
boolean bFirst = true; //是否第一次取文件 23PGq%R  
boolean bStop = false; //停止标志 =cI(d ,  
File tmpFile; //文件下载的临时信息 "jZ-,P=  
DataOutputStream output; //输出到文件的输出流 .#gzP2 [q  
Ml_^ `vn  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) o-5TC  
public SiteFileFetch(SiteInfoBean bean) throws IOException !L(^(;$Kgr  
{ C dn J&N{  
siteInfoBean = bean; TjH][bH5  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Y2AJ+ |  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); pBHRa?Y5  
if(tmpFile.exists ()) tQ)qCk07  
{ ZK,G v  
bFirst = false; 6P3*Z  
read_nPos(); 4?kcv59  
} ( .:e,l{U%  
else ah"o~Cbj  
{ >MZ/|`[M  
nStartPos = new long[bean.getNSplitter()]; h p1Bi  
nEndPos = new long[bean.getNSplitter()]; 7Q 3k 7  
} Txu/{ M,  
BGSw~6  
BPrt'Nc  
{ 6il`>=C  
} *4'"2"  
{7[Ox<Ho  
N2G{<>=  
public void run() $'vU2L  
{ F9PxSk_\9  
//获得文件长度 6nn *]|7  
//分割文件 /~1+i'7V.,  
//实例FileSplitterFetch llq<egZpm  
//启动FileSplitterFetch线程 |!ELV 7?(  
//等待子线程返回 "oyo#-5z  
try{ &ZO0r ^  
if(bFirst) _a, s )  
{ F?0Ykjh3  
nFileLength = getFileSize(); OUnA;_  
if(nFileLength == -1) pa+hL,w{6  
{ :OT&  
System.err.println("File Length is not known!"); M\j.8jG  
} E .h*g8bXe  
else if(nFileLength == -2) 0GwR~Z}Z  
{ 6tZI["\   
System.err.println("File is not access!"); awRX1:T#;O  
} ! nx{ X  
else 0GLM(JmK  
{ Gv&V|7-f0  
for(int i=0;i<nStartPos.length;i++) P \I|,  
{ P55fL-vo|}  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); }>\C{ClI  
} kh<2BOV  
for(int i=0;i<nEndPos.length-1;i++) F4QVAOM]U  
{ :jf3HG  
nEndPos = nStartPos[i+1]; kJU2C=m@e2  
}  " bG2:  
nEndPos[nEndPos.length-1] = nFileLength; PT ~D",k  
} G@0&8  
} sO Y:e/_F  
+@UV?"d  
_c07}aQ ],  
//启动子线程 (FV >m  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (7Qo  
for(int i=0;i<nStartPos.length;i++) hH.G#-JO  
{ Jm@oDME_E  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4H/OBR  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), SbZ6t$"  
nStartPos,nEndPos,i); )b)zm2;  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /v}`l  
fileSplitterFetch.start(); *8q.YuZ  
} +ZYn? #IQ  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !D6]JPX  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !-bB559Nv  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2wn2.\v M  
nEndPos = " + nFileLength); \vNU,WO  
// fileSplitterFetch[nPos.length-1].start(); buC{ r,  
$b\P|#A  
xno\s.H%]  
//等待子线程结束 =1! 'QUc  
//int count = 0;  _F{C\}  
//是否结束while循环 ~&O%N  
boolean breakWhile = false; reVgqYp{{-  
}JfjX '  
?2a$*(  
while(!bStop) /reX{Y  
{ u2I Cl  
write_nPos(); @HW*09TG  
Utility.sleep(500); Efe 7gE'  
breakWhile = true; :Tc^y%b0  
g0H[*"hj  
'qi}|I  
for(int i=0;i<nStartPos.length;i++) P>L +t`'  
{ 58K5ZZG  
if(!fileSplitterFetch.bDownOver) RSds8\tk  
{ )jj0^f1!j  
breakWhile = false; J,G lIv.A  
break; c> af  
} GILfbNcd  
} }G=M2V<L  
if(breakWhile) 9L9sqZUB  
break; TC. ,V_  
C~[,z.FvO  
)"LJ hLg  
//count++; SuznN L=/$  
//if(count>4) fM}#ON>Z  
// siteStop(); +p^u^a  
} l%ZhA=TKQ  
tkhCw/  
IID5c" oR  
System.err.println("文件下载结束!"); )Z$!PqRw@u  
} 67TwPvh  
catch(Exception e){e.printStackTrace ();} +(*DT9s+  
} iE{&*.q_}>  
{*KEP  
?upM>69{  
//获得文件长度 H]!"Zq k  
public long getFileSize() >p/`;Kq@  
{ A >$I -T+  
int nFileLength = -1; +"(jjxJm  
try{ !BI;C(,RL  
URL url = new URL(siteInfoBean.getSSiteURL()); #g=XUZ/"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V]N?6\Op  
httpConnection.setRequestProperty("User-Agent","NetFox"); Qd6FH2Pl  
=xrv~  
E9}C  #  
int responseCode=httpConnection.getResponseCode(); {$r[5%L\H  
if(responseCode>=400) *A< 5*Db:F  
{ F?cK- .  
processErrorCode(responseCode); }Lv;!  
return -2; //-2 represent access is error 9l,o P?  
} *H122njH+T  
F/Pep?'  
_U0f=m  
String sHeader; #%s#c0TX  
VX/#1StC  
fh{`Mz,o  
for(int i=1;;i++) q;U,s)Uz^  
{ sGb{9.WK  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2oU_2P  
//Utility.log(in.readLine()); KG@8RtHsQ  
sHeader=httpConnection.getHeaderFieldKey(i); &{RDM~  
if(sHeader!=null) G j1_!.T  
{ 7|D+Ihy;  
if(sHeader.equals("Content-Length")) {[(h[MW#  
{ OTp]Xe/  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \1`O_DF~o  
break; : jx4{V  
} X|[`P<'N<  
} Y~Ifj,\  
else IAEAhqp  
break; 4=.so~9odX  
} ^&)|sP  
} b2]Kx&!  
catch(IOException e){e.printStackTrace ();} jIF |P-  
catch(Exception e){e.printStackTrace ();} Bf:Q2slqI  
B:QHwzd  
XM}hUJJW  
Utility.log(nFileLength); Q^I\cAIB  
a6H%5N  
CJ%I51F`X  
return nFileLength;  9a kH  
} x:7IIvP  
8D].MI^  
bi:8(Q$w:`  
//保存下载信息(文件指针位置) iOdpM{~*  
private void write_nPos() fQ98(+6  
{ Th[dW<  
try{ d"NLE'R  
output = new DataOutputStream(new FileOutputStream(tmpFile)); _FEF x  
output.writeInt(nStartPos.length); Nluoqo ac  
for(int i=0;i<nStartPos.length;i++) X@f}Q`{Ymj  
{ |%v^W3  
// output.writeLong(nPos); 6 r_)sHf  
output.writeLong(fileSplitterFetch.nStartPos); mqJ_W[y7  
output.writeLong(fileSplitterFetch.nEndPos); -![|}pX  
} +*^H#|!  
output.close(); v3qA":(w+(  
} b6M  
catch(IOException e){e.printStackTrace ();} *' X3z@R  
catch(Exception e){e.printStackTrace ();} s <Fl p  
} Kg$ Mx  
`W-Fssu  
4fzZ;2sl}  
//读取保存的下载信息(文件指针位置) akT6^cP^  
private void read_nPos() >3_Gw4S*H  
{ B ZxvJQ  
try{ Q,9oKg  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j.kG};f  
int nCount = input.readInt(); 9/;P->wy  
nStartPos = new long[nCount]; =2 kG%9  
nEndPos = new long[nCount]; EE'!|N3  
for(int i=0;i<nStartPos.length;i++) W%)Y#C  
{ g1o8._f.  
nStartPos = input.readLong(); ;>YzEo  
nEndPos = input.readLong(); %IRi1EmN8  
} o]:9')5^  
input.close(); 0RK!/:'  
} LK"69Qx?5q  
catch(IOException e){e.printStackTrace ();} |I|fMF2K  
catch(Exception e){e.printStackTrace ();} R$Q.sE  
}  *,m;  
? qA]w9x  
F>cv<l =6l  
private void processErrorCode(int nErrorCode) @K]|K]cby  
{ *:NQ&y*uj  
System.err.println("Error Code : " + nErrorCode); :lzrgsW  
} HKr Mim-  
: c[L3rJl  
%[yJ4WL  
//停止文件下载 _l]fkk[T  
public void siteStop() f9\X>zzB2|  
{ hzRYec(  
bStop = true; Gbw2E&a  
for(int i=0;i<nStartPos.length;i++) $\! 7 {6a  
fileSplitterFetch.splitterStop(); ,: ->ErP  
m_l[MG\  
A4ygW:  
} P2*<GjV`S/  
} `#gie$B{  
//负责部分文件的抓取 <o= 8 FO  
**FileSplitterFetch.java ${)b[22":  
*/ #=v~8  
package NetFox; 9M9?%N:ra  
(khL-F  
F:l%O#V  
import java.io.*; 5^KWCS7@  
import java.net.*; OC:T O|S:4  
3Hm/(C  
4g7)iL^#~  
public class FileSplitterFetch extends Thread { Y#3c }qb  
VYhbx 'e  
AFfAtu  
String sURL; //File URL 0AV c  
long nStartPos; //File Snippet Start Position \_U$"/$4VH  
long nEndPos; //File Snippet End Position A={UL  
int nThreadID; //Thread's ID p6WX9\qS(  
boolean bDownOver = false; //Downing is over ,=mS,r7  
boolean bStop = false; //Stop identical D)'bH5  
FileAccessI fileAccessI = null; //File Access interface TW>WHCAm  
$2el&I  
;ZG\p TCA  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y|q3Wa  
{ ?NP1y9Y]i  
this.sURL = sURL; 8Bg;Kh6B  
this.nStartPos = nStart; \r>6`-cs]  
this.nEndPos = nEnd; k: ;WtBC6j  
nThreadID = id; 2wgg7[tGi  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pU7lnS[  
}  v<:R#  
I)W`sBL  
r(2uu  
public void run() Lu0x (/  
{ F*K_+ ?m  
while(nStartPos < nEndPos && !bStop) $D UZ!zaH!  
{ 4YX3+oS  
7`hP?a=  
&(mR> mT  
try{ A_#DJJMm  
URL url = new URL(sURL); !&Pui{F  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D #/Bx[  
httpConnection.setRequestProperty("User-Agent","NetFox"); T${Q.zHY[!  
String sProperty = "bytes="+nStartPos+"-"; N{~Y J$!8  
httpConnection.setRequestProperty("RANGE",sProperty); ]]juN  
Utility.log(sProperty); @Pzu^  
E=w1=,/y  
14'45  
InputStream input = httpConnection.getInputStream(); bNoW?8bZ  
//logResponseHead(httpConnection); z%LIX^q9  
HgkC~'  
E`k@{*Hn&  
byte[] b = new byte[1024]; qWKAM@  
int nRead; ]P2"[y  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |qZ1|  
{ [=]4-q6UN  
nStartPos += fileAccessI.write(b,0,nRead); M[112%[+4  
//if(nThreadID == 1) ohGfp9H  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?8Cq{  
} k,F6Tx  
(DP &B%Sf  
\K<QmK  
Utility.log("Thread " + nThreadID + " is over!"); a+T.^koY  
bDownOver = true; K>l~SDcZ3  
//nPos = fileAccessI.write (b,0,nRead); 78H'ax9m  
} yq iq,=OvP  
catch(Exception e){e.printStackTrace ();} qc~iQSI  
} v2;`f+  
} }k G9!sf  
e,XYVWY%  
w~?~g<q  
//打印回应的头信息 xLZG:^(I  
public void logResponseHead(HttpURLConnection con) a"g!e^  
{ *%t^;&x?  
for(int i=1;;i++) M>8A\;"  
{ 3CGp`~Zf  
String header=con.getHeaderFieldKey(i); a,#j =  
if(header!=null) B[?CbU  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y,e B|  
Utility.log(header+" : "+con.getHeaderField(header)); 0|\$Vp  
else ~PahoRS  
break;  \qK&q  
} ?vHU #  
} :+|Z@KB  
X<; f  
Jl9k``r*  
public void splitterStop() fku<,SV$O4  
{ 4^OY C  
bStop = true; %lGfAYEM=  
} p >t#@Eu|  
cX OK)g#  
&7wd?)s  
} u21EP[[,  
P0PWJ^+,+  
f/Bp.YwL  
/* t=O8f5Pf{  
**FileAccess.java b e^6i:  
*//文件访问(定位,写) 9lH?-~9  
package NetFox; a1y-3 z  
import java.io.*; WoRZW%  
N;j)k;  
s)Cjc.Qs  
public class FileAccessI implements Serializable{ K$_0 `>[  
aC.~&MxFC  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9dUravC7  
RandomAccessFile oSavedFile; t#pS{.I  
long nPos; :| 8M`18lZ  
{"QNJq#:  
Um-[~-  
public FileAccessI() throws IOException 7 uKY24  
{ `o8/(`a  
this("",0); '>ssqBnI  
} M |`U"vO  
&,CiM0  
P8)=Kbd  
public FileAccessI(String sName,long nPos) throws IOException j*jo@N |  
{ }\:Nu Tf  
oSavedFile = new RandomAccessFile(sName,"rw"); &_|#.  
this.nPos = nPos; )vb*Ef  
oSavedFile.seek(nPos); > eIP.,9  
} ]cMqahaY  
+sUFv)!4  
#"\gLr_:m  
public synchronized int write(byte[] b,int nStart,int nLen) ,+{LYF  
{ Pjjewy1}^  
int n = -1; i,4>0o?  
try{ lun\`f 5Q  
oSavedFile.write(b,nStart,nLen); M`i\VG  
n = nLen; {I#]@,  
} mFaZio0GK  
catch(IOException e) D(RTVef  
{ ^y1j.M@q  
e.printStackTrace (); (/j/>9iro  
} O7<]U_"I  
.1Al<OLL  
Ix=}+K/  
return n; Vq?p|wy  
} ,+xB$e  
c>RFdc:U  
q):5JXql~  
} 9-DZU,`P  
EYEnN  
h+&OQ%e=8  
/* `FTy+8mw  
**SiteInfoBean.java =mpV YA  
*/ d0Qd$ .%A  
package NetFox; W=vP]x >J  
IrhA+)pdse  
QPg8;O  
public class SiteInfoBean { fNt`?pW H  
Slher0.Y  
\BZhf?9U  
private String sSiteURL; //Site's URL S(8$S])0  
private String sFilePath; //Saved File's Path a$"Hvrj  
private String sFileName; //Saved File's Name *b/` Ya4  
private int nSplitter; //Count of Splited Downloading File E5xzy/ZQ  
1Z~)RJ<D  
NzOo0tz:  
public SiteInfoBean() IS 2^g>T#1  
{//nSplitter的缺省值为5 <_tT<5'[$u  
//default value of nSplitter is 5 D (m j7oB  
this("","","",5); ;y\IqiA{o  
} (Dl$kGn  
W$OG( m!W>  
s1NKLt  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) FUjl8b-|  
{ W 7\f1}]H  
sSiteURL= sURL; }w<7.I  
sFilePath = sPath; S.m{eur!,E  
sFileName = sName; ,J>5:ht(6  
this.nSplitter = nSpiltter; 3.W@ }   
3#&7-o  
| >htvDL  
} LBsluT  
>>o dZL  
OJ$]V,Z00x  
public String getSSiteURL() J/GSceHF  
{ $[&*Bj11Yg  
return sSiteURL; G <f@#[$'  
} af+IP_6 .  
80/F7q'tn  
.#Z%1U%P.  
public void setSSiteURL(String value) 2.zsCu4lj.  
{ 7-T{a<g  
sSiteURL = value; A1#%`^W9  
} #+5pgD2C  
aL%AQB,  
DRgTe&+  
public String getSFilePath() dhr3,&+T2  
{ CS-uNG6  
return sFilePath; ayD}r#7  
} }mdAM6  
k |%B?\m  
}J1tdko#  
public void setSFilePath(String value) .CU5}Tv-  
{ mkF"   
sFilePath = value; qX   
} Boz@bl mCB  
?yR&/a  
&n?^$LTPY  
public String getSFileName() 9 ;Ox;;w  
{ :Q_<Z@2Y{  
return sFileName; M9@ri^x  
} TGe;HZ  
T{Uc:Z  
c|62jY"$-2  
public void setSFileName(String value) okv1K  
{ C{DvD'^  
sFileName = value; Dzs[GAQ]  
} YY!6/5*/]  
\y)  
J@X'PG< 6B  
public int getNSplitter() ";Rtiiu  
{ $8[r9L!  
return nSplitter; }S$@ Ez6  
} UE ,t8j  
x{c/$+Z[  
<l9-;2L4  
public void setNSplitter(int nCount) !\L/[:n  
{ :!b'Vk  
nSplitter = nCount; 3*)ig@e6  
}  S"$m]  
} yH*6@P4:0=  
Zrr5csE  
D{d>5P?W  
/* HnCzbt@  
**Utility.java m"jV}@agX  
*/ ) ^3avRsC  
package NetFox; p4i]7o@  
16i "Yg!*  
oK%K}{`  
public class Utility { hcbv;[bG  
A\#P*+k0  
o b|BXF  
public Utility() Y +\%  
{ Zg`Mz _?  
S"k *6 U  
'hv k  
} qt^T6+faaQ  
ZMLg;-T.&4  
//线程睡眠 3UQ;X**F  
public static void sleep(int nSecond) B7<Kc  
{ Ch%m  
try{ -O!Zxg5x  
Thread.sleep(nSecond); y>|{YWbp?  
} z,:a8LB#[  
catch(Exception e) njnDW~Snb  
{ -7&Gi +]  
e.printStackTrace (); D<X.\})Md  
} D"ehWLj  
} Xy &uZ  
zyg  }F  
//日志 e^Ky<*Y  
public static void log(String sMsg) z)=+ F]  
{ ,qrQ"r9  
System.err.println(sMsg); GS Q/NYK  
} u% n*gcY  
3^ ~KB'RZ  
V{&rQ@{W  
public static void log(int sMsg) `TPOCxM Mo  
{ \3jW~FV  
System.err.println(sMsg); 9{8GP  
} $gM8{.!  
} <K4 ,7J$}h  
ZzBQe  
U}l14  
/* zf>5,k'x'A  
**TestMethod.java FwZ>{~?3  
*/ ~/ilx#d  
package NetFox; ^F"iP7   
@*DyZB  
\ y{Tn@7  
public class TestMethod { T=:]]nf?M  
)Cw`"n  
;kJA'|GX  
public TestMethod() i^!ez5z  
{ ///xx/weblogic60b2_win.exe b (I2m  
try{ PeE/iZ.  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6q6FB  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %F*|;o7s  
SiteFileFetch fileFetch = new SiteFileFetch(bean); *d',Vuv&[  
fileFetch.start(); d'Axum@  
} u}|%@=xn  
catch(Exception e){e.printStackTrace ();} >xn}N6Rj2~  
ulJX1I=|p  
UD y(v]  
} 2{.QjYw^  
hw~a:kD  
yj(vkifEB  
public static void main(String[] args) ^@_m "^C  
{ +/;*|  
new TestMethod(); zn @N'R/  
} (x$9~;<S*d  
} |fY/i] Ax  
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