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http断点续传简单实现(java)

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/* YCS8qEP&  
**SiteFileFetch.java Nd;,Wz]  
*/ ~2M+Me  
package NetFox; _~a5;[~  
import java.io.*; '1[Bbs  
import java.net.*; Q|i`s=|  
O&ZVu>`g  
Yo a|.2f  
public class SiteFileFetch extends Thread { K f}h{X  
>gGdzL  
*$EcP`K$  
SiteInfoBean siteInfoBean = null; //文件信息Bean T<S_C$O  
long[] nStartPos; //开始位置 X+;{&Efrl  
long[] nEndPos; //结束位置 ^rIe"Kx  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 x>*#cOVz;C  
long nFileLength; //文件长度 BY!M(X jrZ  
boolean bFirst = true; //是否第一次取文件 M?m)<vMr*  
boolean bStop = false; //停止标志 X9/]< Y<!  
File tmpFile; //文件下载的临时信息 9w08)2$ Na  
DataOutputStream output; //输出到文件的输出流 VKb'!Ystl  
8V(-S,  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) $<v{$UOh  
public SiteFileFetch(SiteInfoBean bean) throws IOException $5S/~8g(  
{  SE D_^  
siteInfoBean = bean; D?6ah=:&R  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); V{+5Fas^l  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); iIO_d4Z  
if(tmpFile.exists ()) &HIG776  
{ GK\`8xWE  
bFirst = false; +u]L# ].;  
read_nPos(); HVkq{W|w  
} %MUh_63bB  
else EhK5<v}  
{ XX;MoE~MM  
nStartPos = new long[bean.getNSplitter()]; (Aw!K`0Y1  
nEndPos = new long[bean.getNSplitter()]; Q~S3d  
} {Bm7'%i  
&&er7_Q  
A.>TD=Nz  
F` "bMS  
} 2j( ]Bt:  
'D<84|w:1  
X4dXO5\  
public void run() H6/C7  
{ AW< z7B D  
//获得文件长度 /%9CR'%*c  
//分割文件 sV5S>*A[  
//实例FileSplitterFetch `(6g87h  
//启动FileSplitterFetch线程 HDV$y=oHh  
//等待子线程返回 0 $_0T  
try{ cBz_L"5vr[  
if(bFirst) UKfpoDhEe  
{ A<|]>[ax  
nFileLength = getFileSize(); ,)](h+zl_6  
if(nFileLength == -1) l d@B  
{ ]5`Y^hS_g  
System.err.println("File Length is not known!"); .W1i3Z6g  
} -/z#?J\  
else if(nFileLength == -2) "[M k5tM  
{ Z9vJF.clO  
System.err.println("File is not access!"); [S#QGB19  
} >UDb:N[  
else Wi3St`$  
{ 6i.!C5YX]  
for(int i=0;i<nStartPos.length;i++) Y[WL}:"93  
{ UYW{A G2C  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); , s .{R  
} Weu%&u-  
for(int i=0;i<nEndPos.length-1;i++) %}x$YD O  
{ =V(|3?N  
nEndPos = nStartPos[i+1]; - BE.a<  
} iZbY@-3fc  
nEndPos[nEndPos.length-1] = nFileLength; ZclZD{%8J  
} $`O%bsjX  
} 0CFON2I  
"FfIq;  
Y,;$RV@g  
//启动子线程 8M9}os  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x;L.j7lzA;  
for(int i=0;i<nStartPos.length;i++) u#sbr8Y  
{ NiPa-yRh  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1e(Q I) ~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !1<?ddH6  
nStartPos,nEndPos,i); g Xi& S  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P6 & _q  
fileSplitterFetch.start(); Q@"mL  
} E` aAPk_ y  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fy'/8Yv#L  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1);  XBF]|}%  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", z0Bw+&^]}  
nEndPos = " + nFileLength); NL76 jF  
// fileSplitterFetch[nPos.length-1].start(); {u4=*> ?G  
s)<^YASg  
m\O|BMHn  
//等待子线程结束 c2iPm9"eh  
//int count = 0; C\WU<!  
//是否结束while循环 ;DXcEzV  
boolean breakWhile = false; IS9}@5`'  
uv$t>_^  
? pkg1F7  
while(!bStop) c5f8pa *  
{ M^twD*  
write_nPos(); *6b$l.Vs  
Utility.sleep(500); G*x"drP  
breakWhile = true; 6;8Jy  
z/&2Se:  
Yo$NE  
for(int i=0;i<nStartPos.length;i++) qh<h|C]V  
{ _xVtB1@kLM  
if(!fileSplitterFetch.bDownOver) 1s@%q <  
{ Y::I_6[eV  
breakWhile = false; 5\6S5JyIL  
break; pf'-(W+  
} ]l.qp5eQ  
} t:?8I9d  
if(breakWhile) gfW8s+  
break;  {Hp*BE   
h;(#^+LH  
M]JD(  
//count++; zLB7'7oP  
//if(count>4) X\dPQwasM  
// siteStop(); 7Ne`F(c  
} 8ezdU"  
Rl2*oOVz  
W@( EEMhw  
System.err.println("文件下载结束!"); O%KP,q&}Y  
} & &\HE7*  
catch(Exception e){e.printStackTrace ();} O=C z*j  
} |re>YQ!zd  
?z]h Ysy  
-(Y(K!n  
//获得文件长度 %Gk?f=e  
public long getFileSize() (g8<"< N?  
{ =ZaTD-%id  
int nFileLength = -1; ee0)%hc1t  
try{ vg6 ' ^5S7  
URL url = new URL(siteInfoBean.getSSiteURL()); 3TDjWW;#~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @TTB$  
httpConnection.setRequestProperty("User-Agent","NetFox"); }%;o#!<N(@  
V&75n.L  
j~)GZV  
int responseCode=httpConnection.getResponseCode(); uR:@7n  
if(responseCode>=400) @},25"x)  
{ p[zKc2TPk  
processErrorCode(responseCode); ?k*%r;e>  
return -2; //-2 represent access is error  3~mi  
} 9 Z 5!3  
!Xzne_V<  
JQt Bt2  
String sHeader; tf5h/:  
{M.OOEcIp  
#J,?oe=<4  
for(int i=1;;i++) N5SePA\ ,?  
{ >5aZ?#TS1  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wM"P JG  
//Utility.log(in.readLine()); 2qF ?%  
sHeader=httpConnection.getHeaderFieldKey(i); R2 I 7d'|v  
if(sHeader!=null) <Xsy{7  
{ {H5a.+-(bE  
if(sHeader.equals("Content-Length")) ~_ 8X%ut y  
{ ])sIQ{P  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l|z0aF;z  
break; b,8\i|*!f  
} `=zlS"dQ  
} qkEre  
else M!9gOAQP  
break; U>,E]'  
} ka^sOC+Y  
} M'n2j  
catch(IOException e){e.printStackTrace ();} 122%KS  
catch(Exception e){e.printStackTrace ();} 8-2e4^ g(  
yyj?hR@rZ  
w4m)lQM  
Utility.log(nFileLength); {7%W /C#A  
DLWG0$#!  
zv^km5by  
return nFileLength; DhVF^=x$  
} R@+%~"Z  
gNsas:iGM  
/mM#nS  
//保存下载信息(文件指针位置) o<Esh;;*nm  
private void write_nPos() -Dx_:k|k  
{ \x,q(npHi  
try{ {c;][>l  
output = new DataOutputStream(new FileOutputStream(tmpFile)); r? w^#V  
output.writeInt(nStartPos.length); N '8u}WO  
for(int i=0;i<nStartPos.length;i++) E=-ed9({:  
{ cQ?eL,z  
// output.writeLong(nPos); tTMYqg zUk  
output.writeLong(fileSplitterFetch.nStartPos); O)$rC  
output.writeLong(fileSplitterFetch.nEndPos); N}j]S{j}'  
} -8r';zR  
output.close(); &7i o/d\/  
} ~^{jfHTlv  
catch(IOException e){e.printStackTrace ();} 5-3.7CO$  
catch(Exception e){e.printStackTrace ();} gyz#:z$p^  
} Q (3Na6  
%a_ rYrL  
w=ib@_:f  
//读取保存的下载信息(文件指针位置) bK\Mn95]  
private void read_nPos() |[RoR  
{ YPV@/n[N  
try{ Vw^2TRU  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T ke3X\|  
int nCount = input.readInt(); CWTPf1?eB  
nStartPos = new long[nCount]; x'4q`xDa  
nEndPos = new long[nCount]; .d JX,^  
for(int i=0;i<nStartPos.length;i++) GV+K] KDI  
{ kgq"b)  
nStartPos = input.readLong(); y .O%  
nEndPos = input.readLong(); m>H+noc^  
}  ?)_?YLi  
input.close(); fbG+.'  
} g[NmVY-o  
catch(IOException e){e.printStackTrace ();} 8zMt&5jD  
catch(Exception e){e.printStackTrace ();} ]f3[I3;K  
} W7F1o[  
$j+RUelFY  
9?jD90@ }  
private void processErrorCode(int nErrorCode) BrHw02G  
{ V>$A\AWw  
System.err.println("Error Code : " + nErrorCode); ?F^$4:  
} }f~:>N#  
+ Z7 L&BI  
,[} XK9  
//停止文件下载 R;G"LT  
public void siteStop() 7z_EX8^  
{ JJHfg)  
bStop = true; _uYidtxo=  
for(int i=0;i<nStartPos.length;i++) \4/zvlo]h  
fileSplitterFetch.splitterStop(); OH(w3:;[8  
prWK U  
Q.]$t 2J  
} lBpy0lo#  
} '^npZa'%sW  
//负责部分文件的抓取 U9*uXD1\  
**FileSplitterFetch.java .~nk' m  
*/ _5t~g_(1OK  
package NetFox; +;T `uOF}  
&}:]uC  
;*H@E(g  
import java.io.*; KWq&<X5  
import java.net.*; @PaOQ@  
T4M"s;::1  
dHzQAqb8J  
public class FileSplitterFetch extends Thread { Z7="on4  
\Nvu[P  
}MCh$  
String sURL; //File URL D(' w<9.  
long nStartPos; //File Snippet Start Position i40'U?eG~6  
long nEndPos; //File Snippet End Position +nz6+{li\  
int nThreadID; //Thread's ID 61[ 8I},V  
boolean bDownOver = false; //Downing is over +.EP_2f9  
boolean bStop = false; //Stop identical Az`c? W%  
FileAccessI fileAccessI = null; //File Access interface UdiogXZ  
M2$.Y om[  
\~(scz$  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mSg{0_:  
{ }Ai_peO0a  
this.sURL = sURL; T"b'T>Y  
this.nStartPos = nStart; MMQ^&!H  
this.nEndPos = nEnd; BidTrO  
nThreadID = id; y^*o%2/  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t1Zcr#b>  
} @U 6jd4?)  
+sW;p?K7eO  
mw\ z'  
public void run() :j)v=qul  
{ v7h!'U[/  
while(nStartPos < nEndPos && !bStop) `<"@&N^d  
{ YUGEGXw  
H,{WrWA  
B%.vEk)*  
try{ G[bWjw86O  
URL url = new URL(sURL); }%T8?d]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  v<_wf  
httpConnection.setRequestProperty("User-Agent","NetFox"); &P0jRT3e#Y  
String sProperty = "bytes="+nStartPos+"-"; v>[U*E  
httpConnection.setRequestProperty("RANGE",sProperty); w YEkWB^  
Utility.log(sProperty); &c|3v!  
4X1!t   
vOIzfwYG9  
InputStream input = httpConnection.getInputStream(); - K@mjN  
//logResponseHead(httpConnection); LwI A4$d  
O-=~Bn _  
C)a;zU;9  
byte[] b = new byte[1024]; OpNxd]"T  
int nRead; DO^ J=e  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GBvgVX<  
{ ROWI.|  
nStartPos += fileAccessI.write(b,0,nRead); UA8*8%v  
//if(nThreadID == 1) B1U<m=Y  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sU=7)*$  
} ZHN@&Gg6)  
%3:[0o={d  
J-k/#A4o  
Utility.log("Thread " + nThreadID + " is over!"); K!+IRA@  
bDownOver = true; Y6Mp[=  
//nPos = fileAccessI.write (b,0,nRead); C9FzTg/c  
} vT&) 5nN  
catch(Exception e){e.printStackTrace ();} 4%GwCEnS  
} 2LTMt?  
} `q$a p$?  
YaT6vSz  
%*A|hK+G:W  
//打印回应的头信息 JG:li} N  
public void logResponseHead(HttpURLConnection con) 0^-1/Ec  
{ okkMx"  
for(int i=1;;i++) }<9IH%sgF  
{ ] oMtqkiR  
String header=con.getHeaderFieldKey(i); XH`W(  
if(header!=null) zgnZ72%  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z|k0${iu#  
Utility.log(header+" : "+con.getHeaderField(header)); 6/=0RTd  
else b)(rlX  
break; d$gT,+|vu  
} # GbfFoE  
} }|j \QjH  
_-R&A@  
y[64O x  
public void splitterStop() b;5&V_  
{ h6(\ tRd!\  
bStop = true; (rE.ft5$9  
} ~85>.o2RDW  
e a3f`z  
2gM/".|{  
} tYk!Y/O}  
GpZ}xY'|w,  
@4]} J-3  
/* JGRL&MG4  
**FileAccess.java unB`n'L  
*//文件访问(定位,写) 579<[[6~d2  
package NetFox; '~\\:37+  
import java.io.*; &*YFK/]  
2e<u/M21>  
4c'F.0^  
public class FileAccessI implements Serializable{ i!i=6m.q7  
EZee kxs  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WZQ EBXs  
RandomAccessFile oSavedFile; 6g-Q  
long nPos; >At* jg48  
@d1YN]ede  
3Jh!YzI8  
public FileAccessI() throws IOException l8~s#:v6X  
{ %E k!3t  
this("",0); Ef]<0Tm]:  
} 6.'j \  
dQQ!QbI(.  
RA$%3L[A!  
public FileAccessI(String sName,long nPos) throws IOException ) -^(Su(!  
{ @j`gx M_-O  
oSavedFile = new RandomAccessFile(sName,"rw"); ?e#bq]  
this.nPos = nPos; xiy=D5N.=  
oSavedFile.seek(nPos); &~KAZ}xu  
} Z4s+8cTHn  
WXs?2S*  
R^?9 V=Y<T  
public synchronized int write(byte[] b,int nStart,int nLen) hCPyCq]  
{ #;])/8R%  
int n = -1; >n"4M~I  
try{ H{et2J<H  
oSavedFile.write(b,nStart,nLen); B(1WI_}~  
n = nLen; cfC}"As  
} V)Sw\tS6g  
catch(IOException e) 7SJbrOL4Q-  
{ ;u*I#)7  
e.printStackTrace (); %:!ILN  
} <;lwvO  
ey@{Ng#  
TFG0~"4Cz  
return n; 7tP qez#  
} qORL 7?{  
Lyq[gQjr  
&[7z:`+Y##  
} AaLbJYuKd  
rcAPp  
;Xl {m`E+  
/* FI"KJk'  
**SiteInfoBean.java +.-g`Vyz*  
*/ cb5T-'hY  
package NetFox; y!VL`xV  
PS3jCT  
2 -pv &  
public class SiteInfoBean { 2(2UAB"u  
TZ#^AV=ae  
EYRg,U&'  
private String sSiteURL; //Site's URL q|sT4} =  
private String sFilePath; //Saved File's Path T"/dn%21  
private String sFileName; //Saved File's Name ] B?NDxU  
private int nSplitter; //Count of Splited Downloading File v|R#[vtFd  
8bdx$,$k  
64qqJmG 3  
public SiteInfoBean() q&2L@l3A  
{//nSplitter的缺省值为5 hplxs#  
//default value of nSplitter is 5 sQmJ3 (:HO  
this("","","",5); sLd%m+*p  
} vc C"  
69S*\'L  
0[f[6mm%m  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :?j]W2+kR  
{ Jb6)U]  
sSiteURL= sURL; wv  
sFilePath = sPath; 1T}jK^"  
sFileName = sName; NpH9}, 1i  
this.nSplitter = nSpiltter; 2 b80b50  
%)w7t[A2D  
AAF']z<4_"  
} *RmD%[f  
=wMq!mBd  
Z#%s/TL  
public String getSSiteURL() +`7!4gxwK!  
{ E> N[  
return sSiteURL; >mj WC) U  
} d*dPi^JjC  
7l4}b^>/`  
^"iJ  
public void setSSiteURL(String value) cs 58: G5  
{ K+ |0~/0  
sSiteURL = value; (QS 0  
} {s0!hp  
a1shP};pK  
OkMAqS  
public String getSFilePath() Gi\Z"MiBZ  
{ SB`xr!~A]  
return sFilePath; 2O}X-/H  
} 0j2mTF(C  
Te`MIR  
NNMn,J  
public void setSFilePath(String value) LRR)T: e}q  
{ kP1cwmZ7F  
sFilePath = value; a4 mRu|x  
} |-TxX:O-  
|S]T,`7u  
IdCE<Oj\  
public String getSFileName() R[l~E![!j  
{ `neo.]  
return sFileName; 4|UtE<<b  
}  &\ K  
}L @~!=q*  
Oq:$GME  
public void setSFileName(String value) h0C>z2iH  
{ d.Q<!Au3  
sFileName = value; U ]7;K>.T  
} %' /^[j#  
 +F~B"a  
:kC*<f\  
public int getNSplitter() !+DhH2;)F  
{ 4n*`%V  
return nSplitter; U|b)Bw<P  
} ZAgtVbO7  
>`<qa!9  
o7^0Lo5Z?  
public void setNSplitter(int nCount) .LGA0  
{ xyHv7u%*  
nSplitter = nCount; z'*{V\  
} \wR\i^  
} bc;?O`I<  
o*3\xg  
kG5Uc8 3#G  
/* 3_>=Cv}  
**Utility.java CSH*^nk':O  
*/ !b$]D?=}  
package NetFox; I|Mw*2U  
-;Te+E_  
)x35  
public class Utility { u $B24Cy.  
^O}J',Fm%f  
qC3PKlhv6  
public Utility() 1k`gr&S  
{ eIOMW9Ivt  
2cwJ);Eg2  
xIH= gK  
} mC3:P5/c  
gGx<k3W^  
//线程睡眠 ND/oKM+?  
public static void sleep(int nSecond) h gu\~}kD  
{ wYDdy gS  
try{ Lt i2KY}/%  
Thread.sleep(nSecond); {Es1bO  
} >U(E \`9D  
catch(Exception e) ! %B-y 9\  
{ oi8M6l  
e.printStackTrace (); ge1U1o  
} (hh^?  
} AmQsay#I_  
P<;Puww/  
//日志 EKS?3z%!  
public static void log(String sMsg) iBmvy 7S?  
{ 8"A0@fNz  
System.err.println(sMsg); +11 oVW  
} KUC%Da3  
"rVM23@ tq  
Asy2jw\V  
public static void log(int sMsg) D={$l'y9p  
{ ],vid1E  
System.err.println(sMsg); QU(Lv(/O  
} b`ksTO`}x  
} HBs 6:[q  
`R!2N4|;  
FEX67A8 /;  
/* ;9q$eK%d  
**TestMethod.java W@i|=xS?  
*/ MO|Pv j~[  
package NetFox; ,@I\'os  
J(A+mYr{:  
KFy|,@NI  
public class TestMethod { PZ#aq~>w  
>U?#'e{qW  
L0w2qF  
public TestMethod() 4G hg~0  
{ ///xx/weblogic60b2_win.exe L">m2/ HG  
try{ er2;1TW3E  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P@x@5uC2  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ggpa !R  
SiteFileFetch fileFetch = new SiteFileFetch(bean); B*P;*re  
fileFetch.start(); #WGyQ u  
} s.XxYXR\  
catch(Exception e){e.printStackTrace ();} 6j!a*u:}"  
7[i&EPN  
"{3MXAFe  
} /<dl"PWkJv  
%e_){28 n  
M'oQ<,yW-  
public static void main(String[] args) db}lN  
{ Bo1 t}#7  
new TestMethod(); *Wcq'S  
} 9>ZX@1]m_  
} `6LV XDR  
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