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http断点续传简单实现(java)

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/* fD@d.8nXd  
**SiteFileFetch.java 2!0tD+B  
*/ zYV{ |Z  
package NetFox; Hy4;i^Ik <  
import java.io.*; +z nlf-  
import java.net.*; F oC $X  
|;NfH|43;  
*-PjcF}Y  
public class SiteFileFetch extends Thread { e4Nd  
^7 \kvW  
x?o#}:S  
SiteInfoBean siteInfoBean = null; //文件信息Bean RAl/p9\A+  
long[] nStartPos; //开始位置 [ne51F5_  
long[] nEndPos; //结束位置 FWJ**J  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 4_5f4%S  
long nFileLength; //文件长度 HSysME1X:/  
boolean bFirst = true; //是否第一次取文件 tkZUjQIX  
boolean bStop = false; //停止标志 s8&q8r7%  
File tmpFile; //文件下载的临时信息 ~2\Sn-`  
DataOutputStream output; //输出到文件的输出流 8<"g&+T  
ZeuL*c \  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) -_nQn  
public SiteFileFetch(SiteInfoBean bean) throws IOException VIdKe&,  
{ msgR"T3'  
siteInfoBean = bean; p#jAEY p  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ;>mM9^Jaf  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); rmzzbLTu  
if(tmpFile.exists ()) ya1 aWs~  
{ (9RfsV4^  
bFirst = false; ,2$<Pt;  
read_nPos(); mP\V.^  
} "\EX)u9ze  
else Xi%Og\vm5  
{ i*/i"W<  
nStartPos = new long[bean.getNSplitter()]; WfaMu| L  
nEndPos = new long[bean.getNSplitter()]; 9[zxq`qT}+  
} A0 Nx?  
*gH]R*Q[Rt  
pDlrK&;\z  
BL 1KM2]  
} '>t&fzD0  
OM0r*<D"!  
aGC3&c[Wx  
public void run() rs?Dn6:;B  
{ =gI41Y]  
//获得文件长度 OJpfiZ@Q_  
//分割文件 [TOo 9W  
//实例FileSplitterFetch chL1r9V)v  
//启动FileSplitterFetch线程 pp"#pl  
//等待子线程返回 s4_Dqm  
try{ Zpg;hj5_  
if(bFirst) \"(?k>]E  
{ ,i6E L  
nFileLength = getFileSize(); pi"M*$  
if(nFileLength == -1) AMjr[!44 @  
{ :W,S  
System.err.println("File Length is not known!"); PolJo?HZ  
} {EvT7W  
else if(nFileLength == -2) Cg]|x+  
{ KV$&qM.  
System.err.println("File is not access!"); 6=]Gom&S  
} Q~nVbj?c2v  
else l SdA7  
{ 8^}/T#l  
for(int i=0;i<nStartPos.length;i++) E#+2)Q  
{ RJ@79L *#  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ?)-6~p 4N  
} Mc.{I"c@  
for(int i=0;i<nEndPos.length-1;i++) |gI>Sp%Fu  
{ pFS@yHs  
nEndPos = nStartPos[i+1]; Uo >aQk  
} (0.oE%B",1  
nEndPos[nEndPos.length-1] = nFileLength; [tk x84M8  
} f;^ +q-Q  
} _ +DL   
FzX ;~CA  
>[aR8J/U  
//启动子线程 ^g*Sy, A  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ={%'tv`  
for(int i=0;i<nStartPos.length;i++) )iw-l~y;  
{  B`e/ /  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ck )W=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Zq 85q  
nStartPos,nEndPos,i); L" ejA  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^(^P#EEG  
fileSplitterFetch.start(); m@XX2l9:9  
} ISC>]`  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `[5xncZ-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y"bm4&'  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,5 ka{Q`K  
nEndPos = " + nFileLength); ((A@VcX  
// fileSplitterFetch[nPos.length-1].start(); 0a89<yX  
"O>~osj  
g)czJ=T2  
//等待子线程结束 \JM6zR^Ef  
//int count = 0; m8F$h-  
//是否结束while循环 Ag9GYm  
boolean breakWhile = false; 1ARtFR2C{b  
}{N#JTmjB#  
'O)v@p "  
while(!bStop) <@(\z   
{ >u> E !5O  
write_nPos(); b\ED<'  
Utility.sleep(500); :bct+J}l~  
breakWhile = true; O80Z7  
T+Re1sPr?  
> Hv9Xz  
for(int i=0;i<nStartPos.length;i++) `3\U9ZH23  
{ I%r7L  
if(!fileSplitterFetch.bDownOver) }PK4 KRn  
{ TNqL ')f  
breakWhile = false; 4j3_OUwWZx  
break; ivgX o'=  
} 4A@HR  
} ]2m=lt1  
if(breakWhile) -Ct+W;2  
break; 2?%*UxcO  
<lFHmi$qt{  
sC\?{B0 r  
//count++; R?)Yh.vi=t  
//if(count>4)  it H  
// siteStop(); _DSDY$Ec  
} #9TL5-1y  
aU;X&g+_)  
+!u9_?Tp  
System.err.println("文件下载结束!"); ^Ak?2,xB#+  
} h!dij^bD  
catch(Exception e){e.printStackTrace ();} W^3 Jg2gE  
} q0%QMut%  
!QVhP+l'H  
-%J9!(  
//获得文件长度 %TI3Eb  
public long getFileSize() }OIe!  
{ tF,`v{-up  
int nFileLength = -1; 3L==p`   
try{ @:w^j0+h  
URL url = new URL(siteInfoBean.getSSiteURL()); D,..gsg  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W[I[Xg&  
httpConnection.setRequestProperty("User-Agent","NetFox"); ugN%8N  
\1<aBgK i  
w|G7h=  
int responseCode=httpConnection.getResponseCode(); &I ~'2mpk  
if(responseCode>=400) `%[m%Y9h  
{ 4j0;okQWV'  
processErrorCode(responseCode); }8 ;,2E*z  
return -2; //-2 represent access is error lmcgOTT):  
} nnhI]#,a{  
U^[AW$WzU  
K+ /wJ9^B  
String sHeader; V(K;Gc  
MjQ>& fUK  
XC<'m{^(m  
for(int i=1;;i++) 9E5*%Hu_  
{ y)|d`qC\  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IIMf\JdM  
//Utility.log(in.readLine()); B7qi|Fw  
sHeader=httpConnection.getHeaderFieldKey(i); N4qBCBr(  
if(sHeader!=null) rg[#(  
{ ,]JIp~=nsh  
if(sHeader.equals("Content-Length")) ]Rf$&7`g{  
{ (ZF~   
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (5`(H.(  
break; TPx0LDk%(  
} jp_)NC/~g  
} 07qjWo/t  
else 0;1O;JRw  
break; ZX-A}  
} f[NxqNn  
} 4j+M<g  
catch(IOException e){e.printStackTrace ();} bly `m p8#  
catch(Exception e){e.printStackTrace ();} !}mM"|<  
KX\=wFbP)  
evE:FiDm(j  
Utility.log(nFileLength); EN ^L.q9#  
X pK eN2=p  
`v(!IBP|  
return nFileLength; `|nJAW3  
} DcRoW  
xG4 C 6s  
FS)C<T]t  
//保存下载信息(文件指针位置) V@G|2ZI  
private void write_nPos() /i!/)]*-  
{ l:~ >P[  
try{ OWr\$lm@z$  
output = new DataOutputStream(new FileOutputStream(tmpFile)); /55 3v;l<  
output.writeInt(nStartPos.length); _Nz?fJ:$@  
for(int i=0;i<nStartPos.length;i++) g( "[wqgG  
{ n[a%*i6x  
// output.writeLong(nPos); k^q~ 2  
output.writeLong(fileSplitterFetch.nStartPos); yJ; ;&  
output.writeLong(fileSplitterFetch.nEndPos); L Do~  
} 4e[ 0.2?  
output.close(); gi_f8RP=2a  
} B.Z5+MgM  
catch(IOException e){e.printStackTrace ();} Ql}#mC.>/  
catch(Exception e){e.printStackTrace ();} PEtr8J$uB  
} SrdCLT8  
L?(1 [jB4G  
|M?VmG/6  
//读取保存的下载信息(文件指针位置) \Z/0i|  
private void read_nPos() ll"6K I'X  
{ caTKi8  
try{ Hs.5@l  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,I f9w$(z  
int nCount = input.readInt(); sPX~>8}|VP  
nStartPos = new long[nCount]; TDR#'i  
nEndPos = new long[nCount]; XPi5E"  
for(int i=0;i<nStartPos.length;i++) ,{RWs^W2  
{ FePWr7Ze  
nStartPos = input.readLong(); G>2: WQ/  
nEndPos = input.readLong(); y8di-d3_  
} ,f~8:LHq  
input.close(); cbx( L8  
} ?+{qmqN  
catch(IOException e){e.printStackTrace ();} eGrxS;NY  
catch(Exception e){e.printStackTrace ();} @7Nc*-SM  
} 4Z{ r  
LtDGu})1  
LgSVEQb6\|  
private void processErrorCode(int nErrorCode) 5[+E?4,&  
{ =:^f6"p&Z  
System.err.println("Error Code : " + nErrorCode); WWIQ6EJO  
} l\=He  
W^9=z~-h  
+d8?=LX  
//停止文件下载 5[$Tpn#K7  
public void siteStop() yuB\Z/  
{ +&)&Ny$W  
bStop = true; ==W] 1@s  
for(int i=0;i<nStartPos.length;i++) u6p nO  
fileSplitterFetch.splitterStop(); 4,6nk.$yN  
}zwHUf9q1  
b0Fr]oGp  
} dO[pm0  
} x4S0C[k  
//负责部分文件的抓取 /{\mV(F(  
**FileSplitterFetch.java sJcwN.s  
*/ k/#321Z  
package NetFox; %-, -:e  
mwqe@7  
h*zHmkFR  
import java.io.*; 3ES3, uR  
import java.net.*; RVe UQ%  
tv7A&Z)Rh  
0 8 aZU  
public class FileSplitterFetch extends Thread { b+ v!3|  
UkXf)  
g:>Mooxzi  
String sURL; //File URL %'i`Chc^!;  
long nStartPos; //File Snippet Start Position ;K<W<v5m0N  
long nEndPos; //File Snippet End Position J |TA12s  
int nThreadID; //Thread's ID TYh_uox6  
boolean bDownOver = false; //Downing is over hiA%Tq?  
boolean bStop = false; //Stop identical }CXL\, ;  
FileAccessI fileAccessI = null; //File Access interface FYu=e?L  
s+yX82Y  
bMpCQ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #}{1>g{sXt  
{ 7IH^5r  
this.sURL = sURL; 5PU$D`7it  
this.nStartPos = nStart; x_TtS|   
this.nEndPos = nEnd; {:r8X  
nThreadID = id; H+ Y+8   
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }28,fb /  
} F( Iq8DV  
Ohmi(s   
nXuoRZ  
public void run() 27!9LU  
{ #=B~} _  
while(nStartPos < nEndPos && !bStop) w$5#jJX\  
{ 3d|n\!1r  
:. ja~Q  
<MH| <hP  
try{ ?YO$NYwE  
URL url = new URL(sURL); zg=F;^oZ<  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4uG:*0{Yx  
httpConnection.setRequestProperty("User-Agent","NetFox"); Nn;p1n dN  
String sProperty = "bytes="+nStartPos+"-"; WhHnF*I  
httpConnection.setRequestProperty("RANGE",sProperty); z rV  
Utility.log(sProperty); zT5@wm  
/"M7YPX;  
-K K)}I`  
InputStream input = httpConnection.getInputStream(); `II/nv0jn  
//logResponseHead(httpConnection); L:g!f  
$|yO mh  
ywRw i~  
byte[] b = new byte[1024]; \D37l_  
int nRead; ]7`)|PJ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;w_f^R #  
{ eQUm!9)  
nStartPos += fileAccessI.write(b,0,nRead); aI6fPQe  
//if(nThreadID == 1) . !|3a  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,\BGxGNAmV  
} XfXqq[\N  
pU|SUM  
StP7t  
Utility.log("Thread " + nThreadID + " is over!"); Q'~2,%3<  
bDownOver = true; [z1[4  
//nPos = fileAccessI.write (b,0,nRead); T53|*~u  
} .D`""up|{  
catch(Exception e){e.printStackTrace ();} G3&l|@5  
} P'4jz&4  
} mqg[2VTRP  
+h$) l/>:  
c?NXX&  
//打印回应的头信息 zl W 5$cC[  
public void logResponseHead(HttpURLConnection con) -nQ:RHnd  
{ d|9B3I*I  
for(int i=1;;i++) Lit@ m2{\  
{ tDl1UX  
String header=con.getHeaderFieldKey(i); K)AJx"  
if(header!=null) Q`dzn=  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %y/8i%@6  
Utility.log(header+" : "+con.getHeaderField(header)); #*[G,s#t^  
else :Q\{LBc  
break; >~kSe=Hsb4  
} _O-ZII~  
} uV:;q>XM'%  
xYJ|G=h&A  
vElVw. P  
public void splitterStop() zd+_ BPT  
{ ;MqH)M  
bStop = true; cj:!uhZp7  
} Ed%8| M3  
J0e~s  
RfMrGC^?  
} (P-Bmu!s  
{:VUu?5-t;  
szY=N7\S*  
/* k{op,n#  
**FileAccess.java Q]Fm4  
*//文件访问(定位,写) 'L w4jq  
package NetFox; j7vp@l6`L  
import java.io.*; Zjz< Q-  
\k{UqU+s  
t$sL6|Ww}o  
public class FileAccessI implements Serializable{ |Go?A/'  
&J)q_Z8  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D2`tWRm0  
RandomAccessFile oSavedFile; ic}M)S FD;  
long nPos; HCh;Xi  
@Fp-6J  
!vU$^>zo~  
public FileAccessI() throws IOException L-  -  
{ %=:*yf>}  
this("",0); / -ebx~FX&  
} eGZX 6Q7m  
Y~qv 0O6K  
KKR@u(+"a  
public FileAccessI(String sName,long nPos) throws IOException YEZd8Y  
{ >9o(84AxIH  
oSavedFile = new RandomAccessFile(sName,"rw"); /qW5M4.w  
this.nPos = nPos; 17Q1Xa  
oSavedFile.seek(nPos); }U=|{@%  
}  q$$:<*Uy  
e>-a\g  
fX,L;Se"  
public synchronized int write(byte[] b,int nStart,int nLen) 6B)3SC  
{ !$"DD[~\  
int n = -1; -S]yXZ  
try{ A4,tv#z  
oSavedFile.write(b,nStart,nLen); OC|9~B1  
n = nLen; g0m6D:f  
} Th&* d;  
catch(IOException e) '/^bO#G:  
{ pSQ)DqW  
e.printStackTrace (); y9?~^pTx  
} uaMf3HeYV  
B5>1T[T'-  
>^#OtFHuT)  
return n; TO.71x|  
} H+:SL $+<o  
v$R+5_@[l  
FhZ^/= As  
} i<N[sO  
_~aFzM  
(R _#lRaQ  
/* [C PgfVz  
**SiteInfoBean.java H[ 6L!  
*/ tn-_3C  
package NetFox; m_Owe/BC#m  
IL?mt2IQ>  
\#P>k;D  
public class SiteInfoBean {  D(}w$hi8  
Y<U"}}  
`C~RA, M  
private String sSiteURL; //Site's URL . z/M (  
private String sFilePath; //Saved File's Path WPBn?vb0<  
private String sFileName; //Saved File's Name HS{a^c%  
private int nSplitter; //Count of Splited Downloading File )J?Nfi%  
~n:dHK`  
~$1Zw&X  
public SiteInfoBean() -@49Zh2'  
{//nSplitter的缺省值为5 D-8N Da(`  
//default value of nSplitter is 5 B+G,v:)R6z  
this("","","",5); {EKzPr/  
} cd36f26`"w  
vEJ2d&  
9$&+0  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cPh U q ET  
{ H6ff b)&  
sSiteURL= sURL; U$[C>~r  
sFilePath = sPath; v:*t5M >  
sFileName = sName; u<x2"0f  
this.nSplitter = nSpiltter; =VMV^[&>  
<eU28M?\  
c+PT"/3  
} >#}MDwKZD  
6fvzTd},  
>hcA:\UPk  
public String getSSiteURL() VeixwGZ.  
{ )3_I-Ia  
return sSiteURL; (?SK< 4!  
} !r:X`~\a  
t.sbfLu  
3.q%?S}*  
public void setSSiteURL(String value) uJz<:/rwZ-  
{ O) ks  
sSiteURL = value; 6"^Yn.  
} wB6 ILTu1  
ViV"+b#gu  
}."3&u't  
public String getSFilePath() c@RMy$RTF  
{ $x,?+N  
return sFilePath; i>!7/o  
} [6@{^  
sY4sq5'!  
i"=6n>\  
public void setSFilePath(String value) 1O bxQ_x  
{ Sa!r ,l  
sFilePath = value; ]3@6o*R;  
} pkjf5DWp  
I@VhxJh  
z=TaB^-)  
public String getSFileName() }m Rus<Ax  
{ ]>R|4K_  
return sFileName; `ReTfz;o  
} QJc3@  
+0U{CmH  
lWS @<j  
public void setSFileName(String value) f,9jK9/$  
{ (~F{c0 \C  
sFileName = value; ;D^%)v /i  
} ?Xm!;sS0  
8H4"mxO  
Jx ;" @  
public int getNSplitter() o:kiIZ]  
{ ~F8M_  
return nSplitter; `IQ01FuP  
}  :[:5^R  
 6e,|HV  
D>9~JHB  
public void setNSplitter(int nCount) tx}} Kd  
{ J(*q OGBD  
nSplitter = nCount; aY8"Sw|4  
} >jEn>H?  
} Xz)UH<  
'Eds0"3  
{@Y|"qIN  
/* h8;B+#f`  
**Utility.java 6~8A$:  
*/ 1{N73]-M:  
package NetFox; `YTagUq7  
70NQ9*AAy  
~[|&)}q  
public class Utility { )(~s-x^\z@  
c"BFkw  
m(QGP\Ya  
public Utility() :0,q>w  
{ ( zQ)EHRD  
[:gPp)f,  
v3|-eWet^  
} ;-p1z% u  
SH>L3@Za  
//线程睡眠 M,]C(f>  
public static void sleep(int nSecond) 3R(GO.n=]  
{ 8hWB TUN  
try{ } DY{>D>  
Thread.sleep(nSecond); `>CHE'_  
} fl| 8#\r  
catch(Exception e) m1@ste;$W  
{ dz fR ^Gv  
e.printStackTrace (); TWF6YAQ m  
} QC7Ceeh]4  
} bJc<FL<E  
ySP1,xq  
//日志 L/Cp\|~ O  
public static void log(String sMsg) g_lj/u]P  
{ "?Dov/+Q.  
System.err.println(sMsg); .kpL?_  
} l`9<mL  
VW^6qf/,  
ConXP\M-  
public static void log(int sMsg) y,{=*2Yt  
{ _@I8B  
System.err.println(sMsg); +2%ih !  
} lSv?!2  
} 2E~WcB  
D BDHe-1[+  
oBZ\mk L  
/* Pw`26mB   
**TestMethod.java O@;;GJ  
*/ =zw=J p  
package NetFox; ~jdvxoX-  
a12Q/K  
m0xL'g6F  
public class TestMethod { 6*`KC)a  
x] [/9e  
u6o:~=WwM  
public TestMethod() RlH|G  
{ ///xx/weblogic60b2_win.exe *?|LE C  
try{ \]Nlka  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); VC%{qal;q  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~R7F[R  
SiteFileFetch fileFetch = new SiteFileFetch(bean); $OI 6^  
fileFetch.start(); hdky:2^3  
} [J0f:&7\  
catch(Exception e){e.printStackTrace ();} Ewjzm,2  
N{L'Q0!  
H&K(,4u^  
} i}cqV B?r  
]dzBm!u  
#CKPNk c  
public static void main(String[] args) s Xyc _3N  
{ P%?|V _m  
new TestMethod(); [ kI|Thx  
} sT.;*3{  
} npsDy&  
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