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http断点续传简单实现(java)

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/* rH3U;K!  
**SiteFileFetch.java !l (Vk  
*/ T$5wH )<  
package NetFox; L4>14D\  
import java.io.*; 9>)b6)J D  
import java.net.*; ^kKLi  
)9YDNVo*-  
ZnEgU}g<2  
public class SiteFileFetch extends Thread { (Q*q# U  
0D(8-H  
OS(`H5D  
SiteInfoBean siteInfoBean = null; //文件信息Bean  g\q .  
long[] nStartPos; //开始位置 x MJ-=  
long[] nEndPos; //结束位置  FA+HR  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 .xT?%xSi/  
long nFileLength; //文件长度 (a[BvJf  
boolean bFirst = true; //是否第一次取文件 5pCicwea#  
boolean bStop = false; //停止标志 <= 4$.2ym  
File tmpFile; //文件下载的临时信息 uY]';Ot G  
DataOutputStream output; //输出到文件的输出流 . g#}2:3  
4uXGp sL  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Dvg'  
public SiteFileFetch(SiteInfoBean bean) throws IOException OrkcY39"~a  
{ N]P~`)  
siteInfoBean = bean; gP% <<yl  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); x{1 v(n8+=  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); )Te\6qM  
if(tmpFile.exists ()) Tn7Mt7h  
{ Y&6jFT_  
bFirst = false; 1)X|?ZD]F  
read_nPos(); 7{#p'.nc5  
} $--8%gh dG  
else q8{Bx03m6  
{ imM!Me 0TE  
nStartPos = new long[bean.getNSplitter()]; Z",0 $Gxu  
nEndPos = new long[bean.getNSplitter()]; 1=5"j]0hY  
} +^AdD8U  
opfnIkCe  
/TMVPnvz.  
F5*-HR  
} ]46h!@~aC  
bpY*;o$~  
]Jswxw  
public void run() b] 5dBZ(  
{ ygz2bHpD~  
//获得文件长度 Zux L2W  
//分割文件 w7 MRuAJ4  
//实例FileSplitterFetch x1@,k=qrd  
//启动FileSplitterFetch线程 vPnS`&  
//等待子线程返回 MXA?rjd0  
try{ OX;bA^+}P  
if(bFirst) O60T.MM`  
{ h% -=8l,  
nFileLength = getFileSize(); @/#G2<Vp1  
if(nFileLength == -1) awzlLI<2p  
{ *d8 %FQ  
System.err.println("File Length is not known!"); +3))G  
} ]xS%E r  
else if(nFileLength == -2) <aPZE6z  
{ a j?ZVa6  
System.err.println("File is not access!"); =v3o)lU  
} 7J9<B5U  
else #VhdYDbW  
{ y;az&T  
for(int i=0;i<nStartPos.length;i++) [Q T ;~5  
{ \n}%RD-Ce  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); c]*yo  
} R~=c1bpdq  
for(int i=0;i<nEndPos.length-1;i++) >l0Qd1   
{ =d;a1AO{&  
nEndPos = nStartPos[i+1]; Jq^[^  
}  l7t  
nEndPos[nEndPos.length-1] = nFileLength; (6fD5XtS  
} 1feVFRx'  
} Yup#aeXY/  
tar/no  
Ox)<"8M  
//启动子线程 -o/Vp>_UOE  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; LuRCkKJ  
for(int i=0;i<nStartPos.length;i++) / :$WOQ  
{ x1~AY/)v  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gYt=_+-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V dJ  
nStartPos,nEndPos,i); ^qL<=UC.  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'A[PUSEE  
fileSplitterFetch.start(); .nY}_&  
} K-'uE)  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D&fOZVuqZ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >FeCa h Fn  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Af\@J6viF7  
nEndPos = " + nFileLength); EuHQp7  
// fileSplitterFetch[nPos.length-1].start(); Lum=5zDo  
EwBrOq`C  
13@e mb  
//等待子线程结束 :"y2u   
//int count = 0; h7eb/xEto  
//是否结束while循环 bM'F8 Fi  
boolean breakWhile = false; +184|nJ<2  
$\m:}\%p  
h8WM4 PK  
while(!bStop) LTf)`SN %'  
{ <mJ8~  
write_nPos(); vAP1PQX;  
Utility.sleep(500); b|V <Kp  
breakWhile = true; y:E$n!  
=Fe4-B?I  
{yNeZXA>  
for(int i=0;i<nStartPos.length;i++) dOaOWMrfdf  
{ [m! P(o  
if(!fileSplitterFetch.bDownOver) y=Eb->a){  
{  3B]E2  
breakWhile = false; *QN,w BQ  
break; XnYX@p  
} <XrXs  
} ?yG[VW  
if(breakWhile) a,fcKe&B  
break; `j3 OFC{7E  
xm=Gt$>.o  
I>8_gp\1  
//count++; D<70rBf2  
//if(count>4) F^.]g@g.|  
// siteStop(); U `lp56  
} BJ_"FG  
jcC"vr'u|  
InL_JobE8r  
System.err.println("文件下载结束!"); %4R1rUrgt|  
} IPTFx )]G  
catch(Exception e){e.printStackTrace ();} `#ff`j|a  
} B3yTN6-  
GsO(\hR6^  
|)d%3s\  
//获得文件长度 pcIS}+L  
public long getFileSize() 2asRJ97qES  
{ tW!*W?  
int nFileLength = -1; $J<WFDn9  
try{ %$Fe[#1  
URL url = new URL(siteInfoBean.getSSiteURL()); ZG+FX:v  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P@bPdw!JA  
httpConnection.setRequestProperty("User-Agent","NetFox"); ~[F7M{LS  
K20Hh7cVJ  
h}tC +_"D  
int responseCode=httpConnection.getResponseCode(); R:l&2  
if(responseCode>=400) \ (`2@  
{ |7KWa(V5I  
processErrorCode(responseCode); Sz|kXk6&9  
return -2; //-2 represent access is error $[Ut])4 ~  
} .p Mwa  
ZJ+ad,?,  
!Mgo~h"]#  
String sHeader; EXbZ9 o*  
Txl|F\nK`  
6pb~+=3n  
for(int i=1;;i++) R@uA4Al  
{ )zy ;!  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <l!:#u  
//Utility.log(in.readLine()); tZx}/&m-  
sHeader=httpConnection.getHeaderFieldKey(i); /V cbT >=  
if(sHeader!=null) Jza ?DhSAZ  
{ @+nCNXK  
if(sHeader.equals("Content-Length")) ]H{* Z3S  
{ gB%"JDn8  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @ G!Ir"Q  
break; RnC+]J+?4  
} E 6MeM'sx  
} J8@.qC'!  
else >\~Er@  
break; "*`!.9pt  
} 2z$!}  
} kVCWyZh4  
catch(IOException e){e.printStackTrace ();} T12Zak4.=  
catch(Exception e){e.printStackTrace ();} >S0kiGDV{  
/oJ &\pI  
FSz<R*2  
Utility.log(nFileLength); m8 _yorz  
M/lC&F(  
KSS]%66Y  
return nFileLength; R-<8j`[0  
} | Vlx:  
G{,DoCM5WL  
E ?bqEW(  
//保存下载信息(文件指针位置) - q(a~Ge  
private void write_nPos() }/\`'LQ  
{ p{v*/<.;  
try{ Zl'/Mx g  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Dk$<fMS,7c  
output.writeInt(nStartPos.length); @vib54G  
for(int i=0;i<nStartPos.length;i++) 3*\Q]|SI!  
{ SHB'g){P  
// output.writeLong(nPos); WrRY 3X  
output.writeLong(fileSplitterFetch.nStartPos); BHU$QX  
output.writeLong(fileSplitterFetch.nEndPos); {jwLVKT$  
} x)N QRd  
output.close(); N5`z S79W  
} ? F!c"+C  
catch(IOException e){e.printStackTrace ();} Qv'x+GVW]  
catch(Exception e){e.printStackTrace ();} 4M]l~9;A  
} ZNDi;6e  
0s{7=Ef  
u>vvW|OB[  
//读取保存的下载信息(文件指针位置) }kItVx  
private void read_nPos() n'q:L(`M  
{ K0B<9Wi |  
try{ Fv)E:PnKC  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MwQ4&z#wh  
int nCount = input.readInt(); O^6anUV0  
nStartPos = new long[nCount]; _!vy|,w@e  
nEndPos = new long[nCount]; =-r); d  
for(int i=0;i<nStartPos.length;i++) |N)),/R_  
{ |*b-m k  
nStartPos = input.readLong(); L A A(2  
nEndPos = input.readLong(); XpkOCo02  
} UU[z\^w| E  
input.close(); zG/? wP"  
} &Ruq8n<  
catch(IOException e){e.printStackTrace ();} mvTp,^1  
catch(Exception e){e.printStackTrace ();} !J!&JQ|  
} _emW#*V  
n53c} ^  
3HuGb^SNg  
private void processErrorCode(int nErrorCode) @x743}Y\  
{ QS\wtTXj  
System.err.println("Error Code : " + nErrorCode); P zM yUv  
} FIVC~LDd  
k.c.7%|~;  
S3WUccv  
//停止文件下载 2P^qZDG 8I  
public void siteStop() j`$$BVZ  
{ .L"IG=Uh#  
bStop = true; $)X8'1%6  
for(int i=0;i<nStartPos.length;i++) u3,O)[qV  
fileSplitterFetch.splitterStop(); Uey'c1  
HOCj* O4  
v@M^ukk'}  
} /K1cP>oE  
} ZMiOKVl  
//负责部分文件的抓取 < FO=PM  
**FileSplitterFetch.java 1kUlQ*[<|  
*/ liLhvcd  
package NetFox; %m[ZU<v  
hOj+z?  
f^"pZS  
import java.io.*; f.66N9BHL,  
import java.net.*; kQlwl9  
N]| >\  
t&[<Dl/L  
public class FileSplitterFetch extends Thread { >nih:5J,ja  
H=f| X<8  
]b sabS?  
String sURL; //File URL M3|G^q:l  
long nStartPos; //File Snippet Start Position dkCU U  
long nEndPos; //File Snippet End Position '6>*J  
int nThreadID; //Thread's ID <LXx_{=:  
boolean bDownOver = false; //Downing is over SZ$WC8AX  
boolean bStop = false; //Stop identical v3XM-+Z4  
FileAccessI fileAccessI = null; //File Access interface 10c.#9$  
,5ZQPICF  
=8<~pr-NO  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3b]M\ F9  
{ R)\^*tkz7  
this.sURL = sURL; +DR$>a  
this.nStartPos = nStart; d(ypFd9z  
this.nEndPos = nEnd; T{f$S  
nThreadID = id; [ >\|QS|  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]PoWL;E'  
} a@q c?  
8=joVbs  
udLIAV*  
public void run() u-4@[*^T$  
{ vW vu&3tx  
while(nStartPos < nEndPos && !bStop) DU]KD%kl  
{ VHl1f7%@H  
6W=V8  
7C3YVm6g  
try{ btq 4diW  
URL url = new URL(sURL); 4sn\UuKyL  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x(eX.>o\  
httpConnection.setRequestProperty("User-Agent","NetFox"); bGgpPV  
String sProperty = "bytes="+nStartPos+"-"; e3:L]4t  
httpConnection.setRequestProperty("RANGE",sProperty); o,* D8[  
Utility.log(sProperty); ~eoM 2XlW  
09G47YkSy1  
<.gDg?'3  
InputStream input = httpConnection.getInputStream(); GfEWms8z  
//logResponseHead(httpConnection); m}=E$zPbO  
GbL1<P$V  
9jEH"`qqk  
byte[] b = new byte[1024]; h3 XS t  
int nRead; 0*rD'?)K+  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Pn[oo_)s  
{ ]SRpMZ  
nStartPos += fileAccessI.write(b,0,nRead); HBtk)  
//if(nThreadID == 1) ]- `wXi"  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \y=oZk4  
} q^EY?;Y  
DmLx"%H3  
|3@DCb T  
Utility.log("Thread " + nThreadID + " is over!"); 9_O4 yTL  
bDownOver = true; A!x&,<  
//nPos = fileAccessI.write (b,0,nRead); a6e{bAuq  
} Q-gVg%'7  
catch(Exception e){e.printStackTrace ();} m Jk\$/Kh  
} )(-;H|]?  
} gC/ e]7FNr  
Uza '%R  
:Z6j5V;s  
//打印回应的头信息 >5L_t   
public void logResponseHead(HttpURLConnection con) ~qGW9 4  
{ @CL#B98jl  
for(int i=1;;i++) 1H/I-  
{ {o)pwM"@(  
String header=con.getHeaderFieldKey(i); ^9q#,6  
if(header!=null) g;8 wP5i  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Em@:Qm EN  
Utility.log(header+" : "+con.getHeaderField(header)); 9iZio3m  
else B<m0YD?>~>  
break; 0zq'Nf?#3  
} #m{*]mY@  
} <TRhnz  
5j1d=h  
NBc^(F"  
public void splitterStop() '"\M`G  
{ k<^M >` $  
bStop = true; &EQhk9j  
} LtMM89u  
$%cc[[/U  
9 =;mY  
} 4#03x:/<\  
'!Hs"{~{  
6,3o_"J!  
/* crP2jF!  
**FileAccess.java d"#Zp&#  
*//文件访问(定位,写) !ou#g5Q@z  
package NetFox; ~,HFd`  
import java.io.*; qEST[S V  
mSxn7LG  
?s^3 o{!<W  
public class FileAccessI implements Serializable{ TD}<U8I8_  
cA q3Gh  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0^-1d2Z~  
RandomAccessFile oSavedFile; Wx GD*%  
long nPos; &HM-UC|  
w#9Kt W,tt  
=L" 0]4K  
public FileAccessI() throws IOException PFh ^Z L  
{ /^BC Qaj  
this("",0); =79R;|5  
} Z,38eQpM  
0d9z8y  
8I#ir4z#<  
public FileAccessI(String sName,long nPos) throws IOException ]19VEH  
{ 2L^)k?9>g+  
oSavedFile = new RandomAccessFile(sName,"rw"); @ivd|*?k0  
this.nPos = nPos; L9 D`hefz  
oSavedFile.seek(nPos); d7X&3L%Oq  
} K}R+~<bIY  
'RK"/ZhqE  
PX 8UVA  
public synchronized int write(byte[] b,int nStart,int nLen) r<e%;S  
{ 5XZ! yYB?  
int n = -1; oY18a*_>M1  
try{ }p7iv:P=3  
oSavedFile.write(b,nStart,nLen); }6c>BU}DF  
n = nLen; (hzN(Dh  
} ump~)?_B  
catch(IOException e) KT(Z #$  
{ 6@J=n@J$p  
e.printStackTrace (); ZYwcB]xE z  
} WD[eoi  
7w/IHML  
#dA$k+3  
return n; \WCQ>c?~  
} I9*cEZ!l=e  
n~*".ZC'Y  
%X{EupiFA  
} @Iv;y*y  
$RPW/Lyiq  
}~XWtWbd-  
/* 'jtC#:ePK  
**SiteInfoBean.java Wp=3heCa6  
*/ )\fY1WD  
package NetFox; f&^(f1WO  
pIJXP$v3  
+$,Re.WnP  
public class SiteInfoBean { O<gfZ>  
k&]nF,f  
Z',!LK!  
private String sSiteURL; //Site's URL Ma[EgG  
private String sFilePath; //Saved File's Path &7aWVKon  
private String sFileName; //Saved File's Name e`D}[G#  
private int nSplitter; //Count of Splited Downloading File /~[Lr   
6Xlzdt  
~7P)$[  
public SiteInfoBean() W7i|uTM  
{//nSplitter的缺省值为5 t;&XIG~  
//default value of nSplitter is 5 NI >%v  
this("","","",5); 4>hHUz[_  
} aLJm%uW6m&  
g{65QP  
*gbK :*_J  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \c=I!<9  
{ {*ak>Wud  
sSiteURL= sURL; $cCC 1=dW  
sFilePath = sPath; [. 5m}V  
sFileName = sName; T # \  
this.nSplitter = nSpiltter; "ZuuSi  
x*Lt]]A  
ff"wg\O4  
} %@/^UE:  
'$K E= Jy  
jVj5; }  
public String getSSiteURL() XIeLu"TSL  
{ ~Iu!B Y  
return sSiteURL; ^:eZpQ [,  
} ;;Q^/rkC  
)O]T}eI  
WSkGVQu  
public void setSSiteURL(String value) =l ,P'E  
{ AlSO  
sSiteURL = value; xt{'Be&Ya+  
} +L(amq;S  
&NE e-cb[  
EdJL&*  
public String getSFilePath() )D)5 `n)  
{ /:&!o2&1H  
return sFilePath; l>?c AB[  
} p*Bty@CRi  
hRcb}>pr  
7|P kc(O  
public void setSFilePath(String value) U@lc 1#  
{ NR{wq|"  
sFilePath = value; &1xCPKIr  
} aER|5!7(2\  
9(CvGzco <  
|y\Km  
public String getSFileName() OZ,kz2SF#  
{ /HC:H,"i  
return sFileName; [m t.2.  
} f^WTsh]  
--$o$EP`  
1^p/#jt  
public void setSFileName(String value) '=\}dav!  
{ h~MV=7 lE  
sFileName = value; Y Y:Bw W:  
} f& 4_:'-,  
JE?p'77C  
$Gn.G_"v  
public int getNSplitter() e%4?-{(  
{ TOYK'|lwM  
return nSplitter; z3fv}_\z  
} bf3!|Um  
yqK4 "F&  
qfkHGW?1/j  
public void setNSplitter(int nCount) |.IH4 K  
{ Pf?kNJ*Tv)  
nSplitter = nCount; *dzZOe>,  
} KaGUpHw  
} "cH RGJG#  
"q4tvcK.  
B{-7  
/* D7ex{SVA)  
**Utility.java # kI>  
*/ R#(0C(FI^  
package NetFox; F /b`[  
X>%nzY]m  
W+XWS,(  
public class Utility { 7\u+%i;YZ  
zd?@xno  
jjpYg  
public Utility() *OVB;]D3+  
{ 6Z/`p~e  
+)Te)^&v%  
Z5{a7U4z_  
} &dtk&P{  
Ycm)PU["  
//线程睡眠 R+sT &d  
public static void sleep(int nSecond) @nxo Bc !P  
{ R{hX--|j  
try{ bIKg>U'5d  
Thread.sleep(nSecond); ]m]`J|%i  
} bP,<^zA|X  
catch(Exception e) 'Pz%c}hJ  
{ ]AP1+ &9fN  
e.printStackTrace (); #XV=,81w  
} Er~17$b  
} 8 WP>u8&  
dWY%bb  
//日志 &}ZmT>q`$  
public static void log(String sMsg) D{|qP nE4  
{ <QtZ6-;_f  
System.err.println(sMsg); fF:57*ys  
} -F[8 ZiZ  
8$Q`wRt(%  
?-??>& z  
public static void log(int sMsg) .@dC]$2=  
{ U%{GLO   
System.err.println(sMsg); wI#8|,]"z  
} A#u U ]S  
} WlL(NrVA@@  
2FcL-?  
4Nm>5*]  
/* }E`Y.= S  
**TestMethod.java 3f|}p{3  
*/ b`0tfXzS5  
package NetFox; L aTcBcI  
` ]|X_!J-  
UuG%5 ZC  
public class TestMethod { ! VwU=5  
 Xo^8o0xi  
AXfU$~  
public TestMethod() ,OZ  
{ ///xx/weblogic60b2_win.exe h\RX/C!+  
try{ p_r`"  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $QX$rN  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @xG&K{j  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?7{U=1gb$  
fileFetch.start(); 5Z=4%P*I  
} *% -<Ldv  
catch(Exception e){e.printStackTrace ();} .soCU8i3  
EZtU6kW"  
Xj?Wvt  
} ~{x1/eH  
~%hdy @  
 ` Xc7b  
public static void main(String[] args) D?|D)"?qb  
{  %zavSm"  
new TestMethod(); S :HOlJze  
} ,(jJOFf  
} {1GJ,['qL  
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