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http断点续传简单实现(java)

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/* /2(F  
**SiteFileFetch.java m{|n.b  
*/ !v=ha%w{  
package NetFox; NT'Yh  
import java.io.*; PR0]:t)E  
import java.net.*; /<~IKVz\&  
t*#T~3p  
J5wq}<8  
public class SiteFileFetch extends Thread { 9L,T@#7  
qM'5cxe  
KMa?2cJH#  
SiteInfoBean siteInfoBean = null; //文件信息Bean va\cE*,@ns  
long[] nStartPos; //开始位置 q_bB/   
long[] nEndPos; //结束位置 E),T,   
FileSplitterFetch[] fileSplitterFetch; //子线程对象 =zdRoXBY[b  
long nFileLength; //文件长度 A7se#"w  
boolean bFirst = true; //是否第一次取文件 O#g31?TO  
boolean bStop = false; //停止标志 ~Q5HM  
File tmpFile; //文件下载的临时信息 Wp $\>  
DataOutputStream output; //输出到文件的输出流 n7vi@^lf(  
V! p;ME  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) R4?/7  
public SiteFileFetch(SiteInfoBean bean) throws IOException hI$an%Y(  
{ A]1](VQ)4  
siteInfoBean = bean; ,b{4GU$3  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); <pCZ+Yv E"  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 3f0RMk$pH  
if(tmpFile.exists ()) ~9=g"v  
{ V.qB3 V$  
bFirst = false; oT OMqR{"  
read_nPos(); %0 S0"t  
} 'tekne  
else 8I%1 `V  
{ > ewcD{bt  
nStartPos = new long[bean.getNSplitter()]; ? T9-FGW  
nEndPos = new long[bean.getNSplitter()]; Yyf8B  
} tP3Upw"U  
3$_wAt4w  
Ktoxl+I?  
{>#Ya;E  
} *:iFhKFU  
gwyz)CUkL  
{.v+ iSM  
public void run() t5S S]  
{ W>.qGK|l  
//获得文件长度 p 4=^ UP  
//分割文件 ;TYkJH"  
//实例FileSplitterFetch o}BaZ|iZ2  
//启动FileSplitterFetch线程 /}Max@.`  
//等待子线程返回 k# /_Zd  
try{ $4m{g"xL  
if(bFirst) z?7pn}-  
{ t2>Vj>U  
nFileLength = getFileSize(); BO^e.iB/  
if(nFileLength == -1) RaR$lcG+iY  
{ (c;$^xZK  
System.err.println("File Length is not known!"); 5=eGiF;0\  
} Q/':<QY  
else if(nFileLength == -2) :EZTJu  
{ i9Qx{f88  
System.err.println("File is not access!"); W1 E(( 2  
} U.&=b<f(0r  
else ,Ao8QN  
{ SKGYmleR  
for(int i=0;i<nStartPos.length;i++) v q|W&  
{ @l 1 piz8  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); K:mb$YJ&  
} \%UA6uj  
for(int i=0;i<nEndPos.length-1;i++)  C+_ NG  
{ _("{fJ,A  
nEndPos = nStartPos[i+1]; 8@ b83  
} 1Ypru<.)W  
nEndPos[nEndPos.length-1] = nFileLength; rQU;?[y  
} UPH:$Fk&  
} F[LBQI`zq  
RX '( l  
pl5!Ih6  
//启动子线程 M*nfWQ a  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |VIBSty2d  
for(int i=0;i<nStartPos.length;i++) k z<We/  
{ )tB mSVprl  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R4{2+q=0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;L|%H/SH  
nStartPos,nEndPos,i); 13Q|p,^R  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^$VOC>>9  
fileSplitterFetch.start(); E}UlQq  
} H13|bM<  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dAR):ZKq?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [E+#+-n7  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1N2s[ \q$  
nEndPos = " + nFileLength); : -OHD#>%  
// fileSplitterFetch[nPos.length-1].start(); 99vm7"5hQ  
]w({5i  
c8A //  
//等待子线程结束 BDpeAF8z  
//int count = 0; v*kTTaU&  
//是否结束while循环 ]*?qaIdqu  
boolean breakWhile = false; |:C=j/f   
$5l8V  
@wb V@  
while(!bStop) 88G Q  F  
{ +v/_R{ M  
write_nPos(); 9 u{#S}c`  
Utility.sleep(500); t\X5B]EZ  
breakWhile = true; z>~Hc8*]3  
?Yxk1Y4ig)  
jT%k{"+>+?  
for(int i=0;i<nStartPos.length;i++) i!9yN: m0  
{ K[O'@v  
if(!fileSplitterFetch.bDownOver) >J+hu;I5  
{ )=#QTiJ  
breakWhile = false; ?J|~ G{yH  
break; k1W q$KCwG  
} iXeywO2nP  
} zmF_-Q`c  
if(breakWhile) F|9 W7  
break; Qn_*(CSp  
*s} dtJ  
"9aiin  
//count++; ; 7k@_  
//if(count>4) Mz_*`lRN  
// siteStop(); -:&qNY:Vp  
} /aP4'U8ov  
W&qE_r  
%&0_0BU  
System.err.println("文件下载结束!"); 8V?O=3<a  
} HsO4C)/  
catch(Exception e){e.printStackTrace ();} \:, dWL u  
} Cwl#(; @  
0& 54xP  
`L/\F,  
//获得文件长度 jw]~g+x#$  
public long getFileSize() l*rli[No  
{ D=i)AZqMPp  
int nFileLength = -1; y ~7]9?T  
try{ ^^1rjh1I  
URL url = new URL(siteInfoBean.getSSiteURL()); Q E1DTU  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); # **vIwX-Q  
httpConnection.setRequestProperty("User-Agent","NetFox"); 2Ck'A0d  
bd_&=VLTC  
0j@gC0xu)|  
int responseCode=httpConnection.getResponseCode(); <KlG#7M>  
if(responseCode>=400) eX;C.[&7;8  
{ CvS}U%   
processErrorCode(responseCode); Ksr.'  
return -2; //-2 represent access is error ;rC)*=4#  
} NBU[>P  
e@|/, W   
3=SIIMp7=  
String sHeader; Hx5t![g2K!  
 74i  
}}y~\TB~}  
for(int i=1;;i++) vau0Jn%=ck  
{ z)*7LI  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >VIb|YA  
//Utility.log(in.readLine()); XR3=Y0YDf  
sHeader=httpConnection.getHeaderFieldKey(i); kqdF)Wa am  
if(sHeader!=null) kwF4I )6  
{ 1 w*DU9f  
if(sHeader.equals("Content-Length")) U51C /A  
{ Q4i@y6z  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;w--fqxVl  
break; Pv,Q*gh`  
} x=s=~cu4,  
} 5F&xU$$a-  
else 8$4@U;Vh;  
break; ?( rJ  
} SFP%UfM<  
} !(QDhnx}9c  
catch(IOException e){e.printStackTrace ();} #[=%+*Q  
catch(Exception e){e.printStackTrace ();} D; i%J  
T$)N2]FE  
i^ `]TOP  
Utility.log(nFileLength); ^FJ .C|l(  
y(!J8(yA  
`IN/1=]5  
return nFileLength; AM?62  
} Y_S>S( 0  
oS.fy31p  
7S'3U}Y>VX  
//保存下载信息(文件指针位置) cG{>[Lf  
private void write_nPos() NFxs4:] RT  
{ z86[_l:  
try{ :jo !Yi  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9OI&De5?=V  
output.writeInt(nStartPos.length); b8o}bm{s  
for(int i=0;i<nStartPos.length;i++) /1OzX'5f  
{ JzI/kH~  
// output.writeLong(nPos); l.gt+e  
output.writeLong(fileSplitterFetch.nStartPos); $=) i{kGS@  
output.writeLong(fileSplitterFetch.nEndPos); :s(vn Ie^  
} 1FC' iGI  
output.close(); 1j4(/A  
} UM[<v9NWE  
catch(IOException e){e.printStackTrace ();} 0{0BL@H  
catch(Exception e){e.printStackTrace ();} ^6c=[N$aW  
} ?7n(6kmj4Q  
uj 6dP  
E6 glR  
//读取保存的下载信息(文件指针位置) -`knSR  
private void read_nPos() x.J% c[Q8  
{ k(As^'>  
try{ 1"7Rs}l7  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LNm{}VJ%  
int nCount = input.readInt(); UTT7a"  
nStartPos = new long[nCount]; q4Z9;^S  
nEndPos = new long[nCount]; c^Y&4=>T  
for(int i=0;i<nStartPos.length;i++) wlvhDJ  
{ BM6 J  
nStartPos = input.readLong(); AiMD"7 )c  
nEndPos = input.readLong(); E}&Z=+v}  
} B-EVo&.  
input.close(); b d!|/Lk  
} 6@N?`6Bt  
catch(IOException e){e.printStackTrace ();} pyvZ[R 9  
catch(Exception e){e.printStackTrace ();} D`|.%  
} f/!^QL{  
Nw 74T  
YSQB*FBz  
private void processErrorCode(int nErrorCode) tp4/c'w;)J  
{ 39j "z8 n  
System.err.println("Error Code : " + nErrorCode); |gl~wG1@  
} !+Ia#(  
Yr7%C  
MGoYL \  
//停止文件下载 n4* hQi+d  
public void siteStop() Av3qoH)[<  
{ ?=C?3R  
bStop = true; <[N"W82p  
for(int i=0;i<nStartPos.length;i++) {i}z|'!  
fileSplitterFetch.splitterStop(); R[ 'k&jyi  
JYQ.Y!X1O  
y:\ ^[y IQ  
} zQ[g*  
} C9?R*2L>  
//负责部分文件的抓取 !%pY)69gv  
**FileSplitterFetch.java Ai99:J2k  
*/ Q2 tM~  
package NetFox; c_oI?D9  
[;IW'cXNq  
jSY&P/[ xb  
import java.io.*; =v (MdjwFl  
import java.net.*; ^4D7sS;~3  
.'+*>y!  
m@qM|%(0x  
public class FileSplitterFetch extends Thread { Qf?5"=:#  
0H|U9  
ve#*qz Y  
String sURL; //File URL =e<;B_ ~.  
long nStartPos; //File Snippet Start Position y1zNF$<q  
long nEndPos; //File Snippet End Position m %mA0r  
int nThreadID; //Thread's ID ?B&Z x-krd  
boolean bDownOver = false; //Downing is over BC/oh+FW3  
boolean bStop = false; //Stop identical %FN3/iM  
FileAccessI fileAccessI = null; //File Access interface t6zc$0-j "  
*""JE'wG  
\M@9#bd  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CTqAhL 4}  
{ Y+ZQN>  
this.sURL = sURL;  p^=>N9  
this.nStartPos = nStart; n9qO;X4&  
this.nEndPos = nEnd; #Kr\"o1]  
nThreadID = id; \ow3_^Bk  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u9d4zR  
} bo;;\>k  
IV"OzQONx  
^>?E1J3u  
public void run() J2c.J/o  
{ /U|>  
while(nStartPos < nEndPos && !bStop) vY+{zGF  
{ urJ>dw?FI  
O{0TS^  
~j1.;WId[  
try{ Afpj*o  
URL url = new URL(sURL); i&|fGX?-I  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y Mes314"  
httpConnection.setRequestProperty("User-Agent","NetFox"); +3@d]JfMh  
String sProperty = "bytes="+nStartPos+"-"; yQ^k%hHa  
httpConnection.setRequestProperty("RANGE",sProperty); I=N;F6  
Utility.log(sProperty); bu;3Ib3\  
,&wTUS\  
D][e uB  
InputStream input = httpConnection.getInputStream(); M7$ h  
//logResponseHead(httpConnection); Mn<G9KR  
|*~=w J_  
Jd].e=]pN  
byte[] b = new byte[1024]; kG =nDy  
int nRead; rZ.,\ X_  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kh11Y1Q0d  
{ qb rf;`  
nStartPos += fileAccessI.write(b,0,nRead); yMdAe>@  
//if(nThreadID == 1) 6usy0g D  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lq4vX^S  
} Lk%u(duU^  
U#o5(mK  
?dWfupO{  
Utility.log("Thread " + nThreadID + " is over!"); $O n  
bDownOver = true; /}_OCuJJ,  
//nPos = fileAccessI.write (b,0,nRead); %?o@YwBo^E  
} fS( )F*J  
catch(Exception e){e.printStackTrace ();} ?, dbrQ  
} @;T>*_Yhn  
} c"vF i~Db  
3f 1@<7*  
&VY(W{\eY  
//打印回应的头信息 (-V=&F_  
public void logResponseHead(HttpURLConnection con) oiG@_YtR  
{ ~:65e 8K  
for(int i=1;;i++) ? J;*  
{ %s]l^RZ  
String header=con.getHeaderFieldKey(i); os\"(*dix  
if(header!=null) c0lVt)pr/  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c|f)k:Q  
Utility.log(header+" : "+con.getHeaderField(header)); ##%R|P3  
else ,zCrix 3  
break; wm3fd 7T  
} njz:7]>e  
} Tk9/1C{8  
j( *;W}*^  
z0@)@4z!  
public void splitterStop() In-W,   
{ V;b^b5yZ>  
bStop = true; _g%Wx?K9  
} T>"GH M  
Ek!$Ary  
4r@dV%:%<  
} p[Z'Fl  
nN|zEw]  
?WD|a(  
/* e/;1<5tfj  
**FileAccess.java 4o:  
*//文件访问(定位,写) ^1&xt(G  
package NetFox; 8}Pd- .se  
import java.io.*; fk(l.A$  
4:!KtpR[O  
vt;<+"eps  
public class FileAccessI implements Serializable{ ^k&T?uU  
d|,,,+fS  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jg ~;s  
RandomAccessFile oSavedFile; 3I)!.N[m  
long nPos; 8]DN]\\o  
mp_(ke  
|"[[.Adw9"  
public FileAccessI() throws IOException |51z&dG  
{ )^&,[Q=i  
this("",0); M2[ywab  
} ~I0I#_$'P  
B_u+$Odo  
&Wj %`T{  
public FileAccessI(String sName,long nPos) throws IOException .x__X3P>\  
{ l}>gG[q!  
oSavedFile = new RandomAccessFile(sName,"rw"); /2,s-^  
this.nPos = nPos; sje}E+{[  
oSavedFile.seek(nPos);  E%g_O_  
} LK8K=AA3P  
3r=IO#  
cmQLkT"#K  
public synchronized int write(byte[] b,int nStart,int nLen) 9R XT  
{ /rd6p{F  
int n = -1; ~rBeJZ  
try{ (7nWv43  
oSavedFile.write(b,nStart,nLen); Qtmsk:qm  
n = nLen; ~%Y*2i f  
} _7SOl.5ZE  
catch(IOException e) &`7tX.iMlh  
{ (h0i2>K  
e.printStackTrace (); s[:e '#^  
} -\;x>=#B  
e![|-m%  
IX eb6j8  
return n; thk33ss:  
} f"h{se8C  
a;p3Me7  
LC5NB{b\%>  
} A"S{W^iL  
%YhZ#>WT  
w < p  
/* zosJ=$L  
**SiteInfoBean.java *Yk3y-   
*/ w{[OtGIi3  
package NetFox; pCSR^ua>  
EEQW$W1@  
/}?"O~5M"  
public class SiteInfoBean { R1'bB"$  
]}/LNO*L"  
wK@k}d  
private String sSiteURL; //Site's URL Mn(:qQo^&`  
private String sFilePath; //Saved File's Path brN:Ypf-e  
private String sFileName; //Saved File's Name 4LYeacL B  
private int nSplitter; //Count of Splited Downloading File wU_e/+0h  
Q7`}4c)  
Qcu1&t\C  
public SiteInfoBean() Xj.Tg1^K"  
{//nSplitter的缺省值为5 hV_eb6aj}P  
//default value of nSplitter is 5 #$(F&>pj  
this("","","",5); ^{8r(1,  
} _yT Gv-  
' }rUbJo  
]zHUF!a*  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ysA~Nq@  
{ oB8u[ !  
sSiteURL= sURL; i Xtar;%  
sFilePath = sPath; B8z3W9  
sFileName = sName; ,u|vpN  
this.nSplitter = nSpiltter; q4$zsw  
ml 7]s N(  
EBS04]5ul  
} e!*d(lHKos  
0|8c2{9X,  
}6} Gj8Nb  
public String getSSiteURL() ~;W]0d4,\  
{ AE1!u{  
return sSiteURL; y5>859"h  
} U3MfEM!x  
 ^G{3x  
ny17(Y =  
public void setSSiteURL(String value) xd\k;nq  
{ w> `3{MTQ  
sSiteURL = value; j{EN %  
} uWR\#D'  
$trvNbco  
]ERPWW;^  
public String getSFilePath() Ia:n<sZU  
{ $x]'6  
return sFilePath; [;II2[5 ,  
} ]V J$;v'{[  
3dNOXk, #  
9RwD_`D(MN  
public void setSFilePath(String value) HF}%Ow  
{ +`l >_u'  
sFilePath = value; uiDK&@RS  
} 9vT@ mqKu  
^2OBc  
hZ!N8nWwNR  
public String getSFileName() >5)E\4r-  
{ A!&p,KfT5+  
return sFileName; 2MmqGB}YcW  
} hZ-No  
UOH2I+@V  
5+dQGcE@  
public void setSFileName(String value) V*SKWP  
{ +=hiLfnE  
sFileName = value; &!#,p{}ccU  
} roYoxF;\  
}|MGYS)  
W}V L3s  
public int getNSplitter() FR _R"p  
{ ?B@(W(I  
return nSplitter; Z8+{ -  
} ^Fgmwa'  
ZWaHG_ U)  
.)|r!X  
public void setNSplitter(int nCount) =Y>_b 2  
{ ^il'Q_-{  
nSplitter = nCount; ]&w>p#_C  
} si,fs%D&  
} 3{ i'8  
ZP5.?A-=C  
v|`f8M2  
/* R"#DR^.;  
**Utility.java ENm\1  
*/ :%Na-j9hV)  
package NetFox; >t')ZSjRs  
:<f7;.  
K?:rrd=7q  
public class Utility { ST1PSuC~  
_x_om#~n  
EaGh`*"w(7  
public Utility() c*$&MCh  
{  bz'V50  
jdiFb~5R  
B'>(kZYMs  
} Q9=vgOW+  
),y{.n:wm  
//线程睡眠 #`)zD"CO  
public static void sleep(int nSecond) W-zD1q~0?  
{ _P.+[RS@  
try{ p*E_Po  
Thread.sleep(nSecond); ) D:M_T2  
} S83wAr9T  
catch(Exception e) ;g$s`l/ 4  
{ thcj_BZ8  
e.printStackTrace (); Q.Uyl:^PxU  
} lR_ 4iyqb  
} O?|opD  
q\*",xZxwz  
//日志 DJP)V8]!B  
public static void log(String sMsg) ~.7r  
{ Y}%=:Yt  
System.err.println(sMsg); Q`}1 B   
} YqwDvJWX  
gE'b.04Y9i  
.w2X24Mmb  
public static void log(int sMsg) _!6~o>  
{ OnFx8r:q@%  
System.err.println(sMsg); V}(snG,  
} pH5"g"e1  
} vk:@rOpl  
rCqcl  
M0g!"0?  
/* ~E&drl\  
**TestMethod.java fM,U|  
*/ /Hb'3,jN  
package NetFox; g-j`Ex%  
hyv*+FV;  
X+"8yZz3?  
public class TestMethod { )$V}tr!  
\ a18Hp|%  
Ag QR"Nu6  
public TestMethod() sI4Ql0[  
{ ///xx/weblogic60b2_win.exe zbn0)JO  
try{ !^BXai/  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L9[? qFp  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]X/1u"  
SiteFileFetch fileFetch = new SiteFileFetch(bean); $[txZN  
fileFetch.start(); Ld6j;ZJ';  
} uSp=,2)  
catch(Exception e){e.printStackTrace ();} gK7j~.bb"  
C*Avu  
+~mBo+ ,  
} l}B,SkP^  
2ijw g~_@  
H~x,\|l#  
public static void main(String[] args) qYZ\< h^  
{ j;@7V4'  
new TestMethod(); l<0 BMwS8  
} LQ pUyqR  
} *+TIF"|1  
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