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http断点续传简单实现(java)

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/* (#Wu# F1;  
**SiteFileFetch.java ;A]@4*q  
*/ VHCK2}ps  
package NetFox; ;D:9+E<>a  
import java.io.*; 2 lj'"nm  
import java.net.*; i.3= !6z  
vRs,zL$W  
j6Yy6X]  
public class SiteFileFetch extends Thread { }s(N6a&(  
0w)^)  
\#Pfj &*  
SiteInfoBean siteInfoBean = null; //文件信息Bean { OXFN;2  
long[] nStartPos; //开始位置 %kS(LlL+6  
long[] nEndPos; //结束位置 M%ICdIc'  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 h|,:e;>}  
long nFileLength; //文件长度 _H j!2 '  
boolean bFirst = true; //是否第一次取文件 NWMFtT  
boolean bStop = false; //停止标志 9aze>nxh.  
File tmpFile; //文件下载的临时信息 {so `/EWa  
DataOutputStream output; //输出到文件的输出流 NYrQ$N"  
Fs9I7~L3  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) , Wk?I%>  
public SiteFileFetch(SiteInfoBean bean) throws IOException fh](K'P#^  
{ j@SQ~AS  
siteInfoBean = bean; +y&Tf#.V/A  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); kQEy#JQmB  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); :cF[(i/k4  
if(tmpFile.exists ()) _F$aUtb%O  
{ [co% :xJu  
bFirst = false; U56G.  
read_nPos(); ] lrWgm  
} 4lKq{X5<  
else Dey<OE&  
{ cc~O&?)i  
nStartPos = new long[bean.getNSplitter()]; IOqwCD[  
nEndPos = new long[bean.getNSplitter()]; !bN*\c  
} dwDcR,z?a  
b:tob0TB  
;[M}MFc/`  
z^#;~I @M  
} {(r`k;fB  
?u" 4@  
6YGubH7%_  
public void run() *Zt#U#  
{ KG|n  
//获得文件长度 NT e5  
//分割文件 ,*7 (%k^`  
//实例FileSplitterFetch 3|'>`!hb  
//启动FileSplitterFetch线程 ? 4q4J8j  
//等待子线程返回 A Q'J9  
try{ Cjc6d4~  
if(bFirst) ki?S~'a  
{ 56zL"TF`  
nFileLength = getFileSize(); B9NWW6S  
if(nFileLength == -1) j4|N- :  
{ ykV 5  
System.err.println("File Length is not known!"); Y]/% t{Y  
} A8uVK5  
else if(nFileLength == -2) .QZaGw=,z  
{ ;"dV"W  
System.err.println("File is not access!"); ms*(9l.hOK  
} $a ]_w.@  
else <{V(.=11  
{ @?yX!_YC  
for(int i=0;i<nStartPos.length;i++) ?o81E2TJO  
{ :6vm+5!  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); l49*<nkmq  
} <<+\X:,  
for(int i=0;i<nEndPos.length-1;i++) <}<zgOT[1!  
{ Fcd3H$Na;  
nEndPos = nStartPos[i+1]; `*_mP<Ag  
} 6{n!Cb[e  
nEndPos[nEndPos.length-1] = nFileLength; !g5xq  
} 5=v}W:^v.  
} ow_W%I=6  
9Iwe2lu  
"Zl5<  
//启动子线程 JBE!j-F  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x:),P-~w  
for(int i=0;i<nStartPos.length;i++) }<@b=_>S  
{ S- pV_Ff  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :.Jf0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x[h^[oF0  
nStartPos,nEndPos,i); gkES5Q  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \m(VdE  
fileSplitterFetch.start(); Cd,jDPrw  
} X*/ho  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gtk7)Uh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D^l%{IG   
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g!lWu[d  
nEndPos = " + nFileLength); Cs9.&Y  
// fileSplitterFetch[nPos.length-1].start(); bM{s T"  
x3 q]I8q  
uE%r/:!k4$  
//等待子线程结束 95 ;x=ju  
//int count = 0; M+U9R@  
//是否结束while循环 yeXx',]a  
boolean breakWhile = false; w80oXXs[#  
nuk*.Su  
'*5i)^  
while(!bStop) -I8=T]_D  
{ tnH2sHby  
write_nPos(); "P 7nNa  
Utility.sleep(500); {1 UQ/_  
breakWhile = true; Yw^m  
Fq |Ni$  
9^oKtkoDZ  
for(int i=0;i<nStartPos.length;i++) TW)c#P43K  
{ w_.F' E  
if(!fileSplitterFetch.bDownOver)  .E`\MtA  
{ ~Sj9GxTe  
breakWhile = false; % tS,}ze  
break; K#6P}tf  
} /N=b\-]  
} &e @2  
if(breakWhile) B2>H_dmQ  
break; 'u*D A|HC  
`[f*Zv w  
> V-A;S:  
//count++; zk$FkbX  
//if(count>4) \k.{-nh  
// siteStop(); pMw*9s X  
} [tlI!~Z  
\pPY37l  
>0/i[k-dk  
System.err.println("文件下载结束!"); ur)9x^y  
} z* ^_)Z  
catch(Exception e){e.printStackTrace ();} 8I lunJ  
} s'!Cp=xQF"  
=bfJ^]R  
((H^2KJn  
//获得文件长度 zZL6z4g  
public long getFileSize() wxKX{Bs  
{ pmuvg6@h  
int nFileLength = -1; xN5)   
try{ *=8JIs A>!  
URL url = new URL(siteInfoBean.getSSiteURL()); mWoAO@}Y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /)YNs7gR  
httpConnection.setRequestProperty("User-Agent","NetFox"); %KsEB*' "  
MI/MhkS ?  
|,S+@"0#  
int responseCode=httpConnection.getResponseCode(); 7?#J~.d5  
if(responseCode>=400) e|)hG8FlF  
{ `F-/QX[:  
processErrorCode(responseCode); kjIAep0rT  
return -2; //-2 represent access is error uZNTHD  
} h}[-'>{  
]OM"ZG/^  
3x`|  
String sHeader; *:Y%HAy*  
l{5IUuUi  
^]H5h]U '  
for(int i=1;;i++) ). <-X^@  
{ ^X=ar TE  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F0GxH?  
//Utility.log(in.readLine()); p*< 0"0  
sHeader=httpConnection.getHeaderFieldKey(i); N(; 1o.~  
if(sHeader!=null) '=39+*6?  
{ C6VLy x  
if(sHeader.equals("Content-Length")) F}F&T  
{ ~5NXd)2+Ks  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $mu^G t  
break; IbT=8l,Li  
} FtpK)9/4  
} h?AS{`.1  
else '.on)Zd.  
break; U_Vs.M.p  
} MX$0Op  
} ZT'`hK_up  
catch(IOException e){e.printStackTrace ();} o*b] p-  
catch(Exception e){e.printStackTrace ();} O8+7g+J=!  
6"wlg!k8  
(uXL^oja  
Utility.log(nFileLength); <NR#Y%}-V  
r)lEofX,g+  
? E1<!~  
return nFileLength; :y+2*lV  
} r A`V}>Xj  
8*W#DH!  
XeW<B0~  
//保存下载信息(文件指针位置) xqeyD*s  
private void write_nPos() VQ(jpns5  
{ :G [|CPm-  
try{ /$ w%Q-p  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^&B@Uw5{  
output.writeInt(nStartPos.length); ojafy}  
for(int i=0;i<nStartPos.length;i++) Ghu#XJB?  
{ -?H#LUk  
// output.writeLong(nPos); 2V"B:X\  
output.writeLong(fileSplitterFetch.nStartPos); Q! o'}nA  
output.writeLong(fileSplitterFetch.nEndPos); jfP*"uUK  
} zpzK>DH(  
output.close(); o\[~.";Z  
} aAZZ8V  
catch(IOException e){e.printStackTrace ();} cm&nd'A't  
catch(Exception e){e.printStackTrace ();} N,`$M.|?  
} SbND Y{5RO  
? }Z1bH  
Z 6t56"u  
//读取保存的下载信息(文件指针位置) $3W;=Id=+  
private void read_nPos() <5-[{Q/2z  
{ O_2pIbh  
try{ z#zI1Am(O  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bZ?v-fn\D,  
int nCount = input.readInt(); 9/{(%XwX  
nStartPos = new long[nCount]; SAH-p*.  
nEndPos = new long[nCount]; -j+UMlkB  
for(int i=0;i<nStartPos.length;i++) dV*]f$wQ  
{ &#o~U$GBg  
nStartPos = input.readLong(); O%Scjm-^X  
nEndPos = input.readLong(); 'OE&/ C [  
} =qoWCmg"&  
input.close(); 8{|8G-Mi  
} [8P:?nDDL  
catch(IOException e){e.printStackTrace ();} hP=WFD&  
catch(Exception e){e.printStackTrace ();} I.WvLLK2  
} 3YeG$^y"  
fWCo;4<5?  
S$f9m  
private void processErrorCode(int nErrorCode) 5<iV2Hx  
{ q VjdOY:z  
System.err.println("Error Code : " + nErrorCode); wa(8Hl|Y  
}  Qn^'  
Km%]1X7T6  
A|CmlAW~^  
//停止文件下载 &LmJ!^#  
public void siteStop() s6ZuM/Q  
{ tf =6\p  
bStop = true; KLU-DCb%  
for(int i=0;i<nStartPos.length;i++) :lX!\(E2  
fileSplitterFetch.splitterStop(); ~9?cn  
}elc `jj  
@v$Y7mw3D  
} \@-@Y  
} xqXo0  
//负责部分文件的抓取 t#yk ->,  
**FileSplitterFetch.java (ScxLf=]  
*/ n+! AnKq  
package NetFox; 5(Cl1Yse=r  
]fm'ZY&  
S_iMVHe  
import java.io.*; 2{M^,=^>  
import java.net.*; &w4?)#  
Hh%I0#  
Okgv!Nt8)A  
public class FileSplitterFetch extends Thread { cO-7ke  
l+ 3[ KCE  
zuP B6W^  
String sURL; //File URL ,c$,!.r  
long nStartPos; //File Snippet Start Position F^l[GdUosK  
long nEndPos; //File Snippet End Position B*qi_{Gp  
int nThreadID; //Thread's ID pb^i^tA+A  
boolean bDownOver = false; //Downing is over 2^XGGB0  
boolean bStop = false; //Stop identical SEORSS  
FileAccessI fileAccessI = null; //File Access interface h}-3\8 >  
Pl(Q,e7O]  
@<<<C?CTv  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cD@(/$wt  
{ w;D+y*2  
this.sURL = sURL; J%8(kWQ|  
this.nStartPos = nStart; "-y-iJ  
this.nEndPos = nEnd; Ulhk$CPA  
nThreadID = id; w^(<N7B3T  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H!vax)%-\  
} agkA}O  
yH7F''O7  
(VS5V31"  
public void run() kTKq/G,Ft  
{ sPd Gw~{  
while(nStartPos < nEndPos && !bStop) kSC}aN'  
{ >82@Q^O  
%el"BSB  
/{|EAd{  
try{ Usg K  
URL url = new URL(sURL); <Q$@r?Mu]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wU8Mt#D!  
httpConnection.setRequestProperty("User-Agent","NetFox"); <wZQc  
String sProperty = "bytes="+nStartPos+"-"; 2*rH?dz8E  
httpConnection.setRequestProperty("RANGE",sProperty); g"Ljm7  
Utility.log(sProperty); jN e`;o  
"rTQG6`  
@HT% n  
InputStream input = httpConnection.getInputStream(); aGK?x1_  
//logResponseHead(httpConnection); SH3|sXH<  
!GOM5z,  
e}mD]O}  
byte[] b = new byte[1024]; hp8%.V$f  
int nRead;  rL/H2[d  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r/& sub"X  
{ v. %R}Pa  
nStartPos += fileAccessI.write(b,0,nRead); FE" y\2}  
//if(nThreadID == 1) $m7?3/YG  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )64@2 ~4y  
} ,PlO8;5]  
4!$s}V=6  
p/(~IC "!J  
Utility.log("Thread " + nThreadID + " is over!"); H&F9J ^rC  
bDownOver = true; El<]b7  
//nPos = fileAccessI.write (b,0,nRead); V7#Ffi  
} >tTj[cMJl  
catch(Exception e){e.printStackTrace ();} nYWvTvZ  
} 0ph{  
} P-`M  
ur*T%b9&  
m7&O9?X  
//打印回应的头信息 -yR.<KnL  
public void logResponseHead(HttpURLConnection con) C(S'#cm  
{ OF%B[h&   
for(int i=1;;i++) wg ^sGKN  
{ &P.4(1sC  
String header=con.getHeaderFieldKey(i); "dsU>3u  
if(header!=null) s?zAP O8Sz  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ktK_e  
Utility.log(header+" : "+con.getHeaderField(header)); (&&4J{`W9  
else *o-.6OxZ$  
break; :*t"8;O[  
} nM\eDNK  
} Q F-LU  
1?)Xp|O  
i.=w]S j  
public void splitterStop() lAzj N~V  
{ iQ4);du  
bStop = true; YWMGB#=  
} 76>7=#m0u'  
1J6,]M  
xO1[>W  
} J~B<7O<?!1  
U`,0]"Qk  
$p#%G#T  
/* 76V 6cI=+  
**FileAccess.java Vm5c+;  
*//文件访问(定位,写) ]BtbWKJBqe  
package NetFox; *4U^0e  
import java.io.*; YhbZ'SJ  
[~kdPk  
wUiys/ OVM  
public class FileAccessI implements Serializable{ ET_W-  
WJNl5^  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +zrAG 24q  
RandomAccessFile oSavedFile; XQ%?  
long nPos; n8uv#DsdK  
SF}<{x_  
7@Zx@  
public FileAccessI() throws IOException {g2@6ct  
{ &=<x#h-  
this("",0); \\{J'j>{f  
} S{FROC~1R  
WuPH'4b 5  
:@1eph0  
public FileAccessI(String sName,long nPos) throws IOException %)[+%57{  
{ [01.\eh  
oSavedFile = new RandomAccessFile(sName,"rw"); y;t6sM@  
this.nPos = nPos; *.~6S3}  
oSavedFile.seek(nPos); BYO"u6  
} UbEb&9}  
bV edFm  
=8r 0 (c  
public synchronized int write(byte[] b,int nStart,int nLen) &FH2fMLQ  
{ )x}l3\s  
int n = -1; }Ow>dV?  
try{ e{X6i^% m_  
oSavedFile.write(b,nStart,nLen); 56e r`=ms  
n = nLen; gzjR 6uz  
} ME;n^y\8  
catch(IOException e) VR+<v   
{ Z|_K6v/c  
e.printStackTrace (); qOSg!aft{Q  
} @g2 cC  
>$ NDv  
/n5F(5<  
return n;  %VzKqh  
} \A#1y\ok  
nSF``pp+  
{%VV\qaC  
} hq:&wN 7Q  
ZunCKc  
/;7y{(o  
/* e1>aTu@  
**SiteInfoBean.java }j2Y5  
*/ (RUT{)p[  
package NetFox; ~by]xE1Eg  
N[<H7_/3  
7]x3!AlV  
public class SiteInfoBean { i `s|,"0o  
"S&@F/  
HQUeWCN  
private String sSiteURL; //Site's URL 2:BF[c`  
private String sFilePath; //Saved File's Path %/c+`Wd/l$  
private String sFileName; //Saved File's Name K,6b3kk  
private int nSplitter; //Count of Splited Downloading File :9R=]#uD  
:}h>by=  
>_c5r?]SG  
public SiteInfoBean() "]m+z)lWd  
{//nSplitter的缺省值为5 -pU|hSW*b  
//default value of nSplitter is 5 ) c/% NiN  
this("","","",5); !IC-)C,q  
} SG?Nsp^%`B  
1VF    
5aBAr  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Tx 1 vL  
{ -*~CV:2iq-  
sSiteURL= sURL; mCs#.%dU  
sFilePath = sPath; V~T@6S  
sFileName = sName; WpS1a440  
this.nSplitter = nSpiltter; 4EXB;[ ]  
n4R2^gXAw  
b1gaj"]  
} zP:cE  
L>!8YUz7p$  
uk9g<<3T  
public String getSSiteURL() }m/RZP~=  
{ ^9_U Uzf\  
return sSiteURL; jYVE8Y)my  
} j7MO'RX`&  
'`|A I:L  
)jCo%P/  
public void setSSiteURL(String value) D?~8za`5  
{ [k[u*5hP|F  
sSiteURL = value; mv atUe  
} hKNY+S})g  
rZojY}dWJ  
R#n%cXc|  
public String getSFilePath() 'q>2t}KG  
{ ExSO|g]%  
return sFilePath; v! 42 DA)  
} (f_g7B2&y  
1[E#vdbT  
!Y<oN~<%)  
public void setSFilePath(String value) YB)3X[R+0  
{ E RdL^T>  
sFilePath = value; e,k2vp!<&  
} c=[q(|+O!  
K9[e>  
6*nAo8gl  
public String getSFileName() -h-oMqgu(  
{ G ){g  
return sFileName; <w>/^|]#  
} 8L5!T6+D&  
B/J&l  
:%JC^dV(  
public void setSFileName(String value) K'1~^)*  
{ ]~>K\i  
sFileName = value; m ,>  
} h(B,d,q"  
.> Z,uT^A  
B|%tE{F  
public int getNSplitter() VW@ x=m  
{ ukuo:P<a  
return nSplitter; |xr\H8:(!  
} 6QZ5|T ]  
(QB+%2v  
J$9:jE-4  
public void setNSplitter(int nCount) h?UVDzI!O  
{ b8BD8~;  
nSplitter = nCount; i3mAfDF  
} ]lS@}W\  
} cPn+<M#  
6+dn*_[Z6  
8[bkHfI  
/* t~M $%)h  
**Utility.java (LJ@S eM;  
*/ 68R1AqU_  
package NetFox; MR'o{?{e`  
XD-^w_  
X6RQqen3:  
public class Utility { uXQ >WI@eF  
]M,06P>?  
?mRE'#  
public Utility() Bmo$5$  
{ F9XT lA  
r;iV$Rq !  
:a3LS|W  
} ?M6ag_h3  
$T }Tz7(  
//线程睡眠 S{p}ux[}=  
public static void sleep(int nSecond) noNm^hFL  
{ AxCI 0  
try{ xi'<y  
Thread.sleep(nSecond); %*)2s,8  
} Xt,X_o2m|]  
catch(Exception e) FA>1x*;c  
{ =qoRS0Qa  
e.printStackTrace (); S7n"3.k  
} 8*!|8 BPj^  
} =^h~!ovj:  
o;`!kIQ  
//日志 0jB X5  
public static void log(String sMsg) gs`^~iD]m  
{ V`fL%du,3  
System.err.println(sMsg); `1p 8C%  
} O|v (5 8A  
IlLn4Iw  
<9@7,2  
public static void log(int sMsg) M?o{STt  
{ 6E9N(kFYs  
System.err.println(sMsg); Ly (P=M>"y  
} BSXdvI1y  
} V 2kWiyN  
73DlRt *  
M%=P)cC  
/* g0#q"v55  
**TestMethod.java 6w#nkF  
*/ x3p9GAd#  
package NetFox; vC9@,[  
(:$9%,x  
aIGn9:\  
public class TestMethod { %"7WXOv&z  
=B5E0x  
5RA<Z.  
public TestMethod() (iDBhC;/B  
{ ///xx/weblogic60b2_win.exe sQk|I x  
try{ e)pTC97^L  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Uu2N9.5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mC(u2  
SiteFileFetch fileFetch = new SiteFileFetch(bean); :|XCnK0  
fileFetch.start(); fykI,!  
} 8[\ 79|  
catch(Exception e){e.printStackTrace ();} #)i&DJ^Y  
'yT`ef  
%F$N#YG  
} MTB@CP!u  
>_#)3K1y8  
+rQg7a}  
public static void main(String[] args) ec?1c&E  
{ }|He?[TR  
new TestMethod(); 9H$g?';  
} a"qR J-@  
} *98Ti|  
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