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http断点续传简单实现(java)

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/* @"w4R6l+*  
**SiteFileFetch.java 0G%9 @^B  
*/ W4$o\yA]  
package NetFox; (d9~z  
import java.io.*; ' jciX]g  
import java.net.*; Ky3mz w|  
2& Q\W  
WM bkKC.{J  
public class SiteFileFetch extends Thread { qF)J#$4;6  
8R~<$ xz  
C6+ 5G-Z  
SiteInfoBean siteInfoBean = null; //文件信息Bean O\}C`CiC  
long[] nStartPos; //开始位置 YAi-eL67l  
long[] nEndPos; //结束位置 {v={q1  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 _H]\  
long nFileLength; //文件长度 kHM Jh~  
boolean bFirst = true; //是否第一次取文件 ]m1fo'  
boolean bStop = false; //停止标志 UpoSC  
File tmpFile; //文件下载的临时信息 -@Ap;,=  
DataOutputStream output; //输出到文件的输出流 GwWK'F'2  
d0J /"<  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ! j~wAdHk  
public SiteFileFetch(SiteInfoBean bean) throws IOException DP_b9o \5  
{ Iix,}kzss  
siteInfoBean = bean; vHaM yA-  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Bfb~<rs[  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ct+F\:e  
if(tmpFile.exists ()) ,0'G HQWz$  
{ %G?@Hye3  
bFirst = false; *)^6'4=  
read_nPos(); manw;`Q  
} K)SWM3r  
else [@$ SLl^Y  
{ /<[0o]  
nStartPos = new long[bean.getNSplitter()]; >a3m!`lq  
nEndPos = new long[bean.getNSplitter()]; q~`hn(S  
} 2m Y!gVi  
<^S\&v1C_  
Bc>j5^)8w  
y6 (L=$+B  
} 4[ uqsJB  
e=]SIR()`  
|mT%IR  
public void run() =4TQ*;V:  
{ hY}Q|-|  
//获得文件长度 M1jT+  
//分割文件 kD#T _d  
//实例FileSplitterFetch VoCg,gow  
//启动FileSplitterFetch线程 ^sv|m"  
//等待子线程返回 &X4anH>O  
try{ @52#ZWy  
if(bFirst) w4 yrAj 2  
{ S2X@t>u-  
nFileLength = getFileSize(); cXXZ'y>FP  
if(nFileLength == -1) -"-.Z&#  
{ ,fjY|ip  
System.err.println("File Length is not known!"); Qt u;_  
} rrIyZ@_d9  
else if(nFileLength == -2) =OufafZb  
{ 7cc^n\c?Y  
System.err.println("File is not access!"); -jQ*r$iRE  
} hqRC:p#9  
else 0 kJ8H!~u  
{ Y e0,0Fpw  
for(int i=0;i<nStartPos.length;i++) Mo/R+\u+Y  
{ PRfq_:xy  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); .Ys e/oEo  
} &%J{uRp  
for(int i=0;i<nEndPos.length-1;i++) , ['}9:f9  
{ 4U2{1aN`  
nEndPos = nStartPos[i+1]; .AN1Yt  
} Y9BQLu4F  
nEndPos[nEndPos.length-1] = nFileLength; 8W3zrnc  
} 5OM #_.p  
} le*+(aw  
eKLvBa-{@  
}6Pbjm*  
//启动子线程 AA\)BNM  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <B@NSj  
for(int i=0;i<nStartPos.length;i++) sY<UJlDKT  
{ ~[=<O s  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S1|5+PPs  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6R :hsC$  
nStartPos,nEndPos,i); w!lk&7Q7Z  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zJXK:/  
fileSplitterFetch.start(); 2poo@]M/  
} }u#3hYa  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Jp jHbG  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L|1,/h 8p  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,#;hI{E  
nEndPos = " + nFileLength); MkW=sD_  
// fileSplitterFetch[nPos.length-1].start(); %??v?M*  
Gf8^nfr  
2: QT`e&  
//等待子线程结束 MKbcJZe  
//int count = 0; 628iN%[-  
//是否结束while循环 NV5qF/<M  
boolean breakWhile = false; cGm3LS6]*  
eEXNEgbn  
cB&_':F  
while(!bStop) yPE3Awh5  
{ U\%r33L )  
write_nPos(); RUY7Y?  
Utility.sleep(500); O=__w *<  
breakWhile = true; ")KqPD6k  
*iB&tWv  
eb7UA=[Z  
for(int i=0;i<nStartPos.length;i++) 3cHYe  
{  hh4R  
if(!fileSplitterFetch.bDownOver) a!R*O3  
{ L9jT :2F  
breakWhile = false; ]9_gbQ   
break; ILr=< j  
} 1;[KBYUH  
} +cfcr*  
if(breakWhile) ]QlW{J  
break; *I :c@iCNJ  
pZ8J\4+  
G:*vV#K  
//count++; OROvy  
//if(count>4) $e1.y b%  
// siteStop(); !4Aj#`)  
} 7R:j^"I@  
ezw*Lo!  
LqYyIbsvf  
System.err.println("文件下载结束!"); YM`T"`f  
} S ,F[74K  
catch(Exception e){e.printStackTrace ();} fTXip)n!r  
} P;"moluE;  
@Ommd{0M  
# fqrZ9:@  
//获得文件长度 8XJi}YPQ  
public long getFileSize() 1j<uFhi>  
{ J2}poNmm  
int nFileLength = -1; ^EiU>   
try{ =F|9 ac9X  
URL url = new URL(siteInfoBean.getSSiteURL()); j-d&4,a:c  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \^6[^\@[  
httpConnection.setRequestProperty("User-Agent","NetFox"); 2|x !~e.  
%GTFub0 F  
UYxn? W.g  
int responseCode=httpConnection.getResponseCode(); SY|K9$M^  
if(responseCode>=400) eL~xS: VT  
{ 'IY?=#xr'`  
processErrorCode(responseCode); \ Bj{.jL  
return -2; //-2 represent access is error e1g3a1tnWl  
} /4O))}TX  
WowT!0$  
M(L6PyEa!Y  
String sHeader; # bHkI~  
!p$p 7   
_<RTes  
for(int i=1;;i++) I?Iz5e-  
{ ?L\"qz%gP  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6=n|Ha  
//Utility.log(in.readLine()); 0g30nr)  
sHeader=httpConnection.getHeaderFieldKey(i); f I=G>[  
if(sHeader!=null)  dwk%!%  
{ hZfj$|<  
if(sHeader.equals("Content-Length")) ]y.V#,6e  
{ (o*YGYC  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7d R?70Sz  
break; d4ecF%R  
} Nl[&rZ-&  
} S3/%;=|  
else 1J0gjO)AZ  
break; /?r A|  
} l<XYDb~op  
} ntLEk fK{  
catch(IOException e){e.printStackTrace ();} 8\68NG6o  
catch(Exception e){e.printStackTrace ();} H?O5 "4a  
6!>p<p"Ns  
?fH1?Z\'K  
Utility.log(nFileLength); cO7ii~&%!  
@\nQ{\^;  
:+6W%B  
return nFileLength; q83^?0WD  
} ]=t}8H  
u `/V1  
+rU{-`dy9'  
//保存下载信息(文件指针位置) IDn<5#  
private void write_nPos() ;4!H- qZ  
{ MlYm\x8{M  
try{ (1|wM+)"  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `bBkPH}M  
output.writeInt(nStartPos.length); \}4Y]xjV2  
for(int i=0;i<nStartPos.length;i++) Y Iwa =^  
{ 0?$|F0U"J  
// output.writeLong(nPos); r'Wf4p^Xd  
output.writeLong(fileSplitterFetch.nStartPos); ke8g tbm  
output.writeLong(fileSplitterFetch.nEndPos); -XXsob}/8  
} .KKecdd?=  
output.close(); x?o#}:S  
} RAl/p9\A+  
catch(IOException e){e.printStackTrace ();} xI{fd1  
catch(Exception e){e.printStackTrace ();} R_B0CM<!  
} 27N;>   
)qb'tZz/g_  
a%.W9=h=M(  
//读取保存的下载信息(文件指针位置) 0e<>2AL   
private void read_nPos() s8&q8r7%  
{ ~2\Sn-`  
try{ 8<"g&+T  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xgd-^  
int nCount = input.readInt(); joskKik^  
nStartPos = new long[nCount]; MoN0w.V  
nEndPos = new long[nCount]; lGr=I-=  
for(int i=0;i<nStartPos.length;i++) @Pk<3.S0  
{ B>c$AS\5y  
nStartPos = input.readLong(); m6[}KkW  
nEndPos = input.readLong(); ,V,mz?d^9  
} H2%Qu<Kg2  
input.close(); *V hEl7  
} OY}FtG y  
catch(IOException e){e.printStackTrace ();} ,2$<Pt;  
catch(Exception e){e.printStackTrace ();} lND2Kb  
} OC*28)  
z |llf7:  
O Ol:  
private void processErrorCode(int nErrorCode) `2]0 X#R  
{ V3ht:>c9qs  
System.err.println("Error Code : " + nErrorCode); 1v|-+p42  
} s>o#Ob@4'  
2, )>F"R  
*gH]R*Q[Rt  
//停止文件下载 pDlrK&;\z  
public void siteStop() z*h:Nt%.  
{ )>{ .t=#  
bStop = true; te( H6c#0  
for(int i=0;i<nStartPos.length;i++) }},0#Ap  
fileSplitterFetch.splitterStop(); Rm=p}  
hUi@T}aA|  
uKAI->"  
} <~5O-.G]  
} F:q4cfL6  
//负责部分文件的抓取 NH|I>vyN  
**FileSplitterFetch.java AwNr}9`  
*/ zQulPU  
package NetFox; Zpg;hj5_  
\"(?k>]E  
,i6E L  
import java.io.*; e:Y+-C5  
import java.net.*; 0\:= KIY.  
<z\SKR[  
]TT >3"Dw7  
public class FileSplitterFetch extends Thread { ,5v'hG  
=xm7i#1  
U\Vg&"P  
String sURL; //File URL @ &N  
long nStartPos; //File Snippet Start Position A]!0Z:{h%  
long nEndPos; //File Snippet End Position N\*oL*[j  
int nThreadID; //Thread's ID <b H *f w  
boolean bDownOver = false; //Downing is over ,e43m=KhK  
boolean bStop = false; //Stop identical A .&c>{B7  
FileAccessI fileAccessI = null; //File Access interface RJ@79L *#  
?)-6~p 4N  
X3G593ts  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :W0p3 6"  
{ *|Vf1R]  
this.sURL = sURL; :ZY%-]u7  
this.nStartPos = nStart; 4& cQW)  
this.nEndPos = nEnd; ) n O ^Ay  
nThreadID = id; b_RO%L:"yL  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 neM.M)0  
} c`;oV-f  
~'lT8 n_  
kVQm|frUz  
public void run() G/p\MzDko  
{ ={%'tv`  
while(nStartPos < nEndPos && !bStop) LH(P<k&  
{  B`e/ /  
l%2VA  
fX`u"`o5  
try{ AuQ|CXG-\  
URL url = new URL(sURL); _y[C52,  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R 9` [C  
httpConnection.setRequestProperty("User-Agent","NetFox"); se %#U40*  
String sProperty = "bytes="+nStartPos+"-"; xR0*w7YE  
httpConnection.setRequestProperty("RANGE",sProperty); V8 8u -  
Utility.log(sProperty); &zF>5@fM  
n#x_da-m]  
g7]S  
InputStream input = httpConnection.getInputStream(); U!q2bF<@  
//logResponseHead(httpConnection); "O>~osj  
e2 c'Wab  
MS;^:t1`  
byte[] b = new byte[1024]; }d}gb`Du  
int nRead; 'O)v@p "  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c qCNk  
{ ):PN0.H8  
nStartPos += fileAccessI.write(b,0,nRead); %cn 1d>M+I  
//if(nThreadID == 1) 8_!qoW@B  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,nYa+e  
} ?I^$35  
Bbs1U  
w3,KqF  
Utility.log("Thread " + nThreadID + " is over!"); )1Bz0:  
bDownOver = true; C`[2B0  
//nPos = fileAccessI.write (b,0,nRead); >KuNHuHu  
} n~6$CQ5dF(  
catch(Exception e){e.printStackTrace ();} -lJ|x>PG'  
} A^,u l>!  
} ,JdBVt  
HD KF>S_S  
EM@|^47$  
//打印回应的头信息 0bh 6ay4  
public void logResponseHead(HttpURLConnection con) THq}>QI  
{ -Ct+W;2  
for(int i=1;;i++) |_p7vl"  
{ T3oFgzoO  
String header=con.getHeaderFieldKey(i); :epBd3f  
if(header!=null) A[m?^vk q  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); YaS!YrpI  
Utility.log(header+" : "+con.getHeaderField(header)); Ne+Rs+~4  
else \m|5Aqs  
break; vxPE=!|  
}  it H  
} (Z>?\iNJ  
mh"PAp  
o=Z:0Ukl]  
public void splitterStop() VQ('ejv}/  
{ 3y.+03 W  
bStop = true; k?7"r4Vc)S  
} EwzcB\m  
3\Xk)a_  
}Y7P2W+4?  
} _qPKdGoM  
h!dij^bD  
17'd~-lE  
/* ~s&r.6 DW  
**FileAccess.java t+A*Ws*o  
*//文件访问(定位,写) ^ulgZ2BQ|  
package NetFox; $Mg O)bH  
import java.io.*; MRz f#o<H  
I@m(}  
$)*qoV  
public class FileAccessI implements Serializable{ }OIe!  
?cWwt~N9  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :7X4VHw/  
RandomAccessFile oSavedFile; RDSC@3%  
long nPos; l7T?Yx j  
[@qjy*5p  
$A~aNI  
public FileAccessI() throws IOException -`5]%.E&8  
{ xT&/xZLT  
this("",0); |s/Kb]t  
} r(wf>w3  
40=u/\/K  
\1<aBgK i  
public FileAccessI(String sName,long nPos) throws IOException cPZ\iGy  
{ U~BR8]=G  
oSavedFile = new RandomAccessFile(sName,"rw"); wq.'8Y~BE  
this.nPos = nPos; 0B 1nk!F  
oSavedFile.seek(nPos); =,it`8;  
} 92Gfxld\  
uy2~<)  
-,*m\Fe}  
public synchronized int write(byte[] b,int nStart,int nLen) DW,ERQ^  
{ {w3<dfJ  
int n = -1; J;XO1}9  
try{ kJB:=iq/x$  
oSavedFile.write(b,nStart,nLen); .7 j#F  
n = nLen; Z L0Vx6Ph  
} 38-kl,Vw  
catch(IOException e) @>VX]Qe^X  
{ 5I[:.o0  
e.printStackTrace (); }#.OJub  
} e%:vLE 9  
|^Yz*r?BJ  
D@X"1X!F`G  
return n; ;C=d( pY  
} k {{eyC  
? .B t.  
T*B`8P  
} 'S}3lsIE  
hB<(~L? A]  
ghW`xm87  
/* rg[#(  
**SiteInfoBean.java +Goh`!$Rj9  
*/ ])qnPoQ<n  
package NetFox; 4J'0k<5S  
3`D*AFQc  
Vq#0MY)2gS  
public class SiteInfoBean { a"4X7 D+  
21<Sfsc$  
C+!=C{@7di  
private String sSiteURL; //Site's URL Y[b08{/  
private String sFilePath; //Saved File's Path .(p_YjIA  
private String sFileName; //Saved File's Name P;XA|`&  
private int nSplitter; //Count of Splited Downloading File kn$SG  
Ot=nKdP}D  
{gEz;:!):  
public SiteInfoBean() f[NxqNn  
{//nSplitter的缺省值为5 G?~Yw'R^8  
//default value of nSplitter is 5 Q>X1 :Zn3  
this("","","",5); pdN8 hJ  
} zO9WqP_`iR  
DI-&P3iGx  
oEZhKVyc.y  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J7WNgl% u  
{ zvnd@y{[  
sSiteURL= sURL; /!5cf;kl*l  
sFilePath = sPath; m_  wvi  
sFileName = sName; oP 7)  
this.nSplitter = nSpiltter; _o?aO C  
t#f-3zd9  
w"kBAi&  
} X/%!p<}:'  
:zIB3nT^  
JC$_Pg!  
public String getSSiteURL() g]MgT-C|  
{ |LZ+_  
return sSiteURL; M?sTz@tqq  
} .pxUO3g  
FS)C<T]t  
8rBa}v9  
public void setSSiteURL(String value) &-IkM%_A9  
{ NU.4_cixb  
sSiteURL = value; 'T|QG@q  
} P _Gu~B!Y  
d@ZXCiA},  
H2g#'SK@  
public String getSFilePath() {P?p*2J'  
{ Hjs#p{t[  
return sFilePath; btC<>(kl&  
} uu0t}3l  
M_$;"NS+}  
j~in%|^  
public void setSFilePath(String value) [ p0_I7  
{ 6m(+X M S  
sFilePath = value; %,8 "cM`D  
} 9QF,ynE  
s}gdi  
W+V &  
public String getSFileName() qpf|.m  
{ Sng3B  
return sFileName; /sB,)> X  
} l,QO+ >)z  
5@bmm]  
;;^?vS  
public void setSFileName(String value) D_z&G)  
{ Y!u">M#@  
sFileName = value; N4yQ,tG>aa  
} LmROG-9  
C91'dM  
R6o07.]  
public int getNSplitter() ]K5j(1EN  
{ bM W}.v!  
return nSplitter; *$t=Lh  
} 7W/55ZTmJ  
1OK~*=/4  
a\ MJh+K  
public void setNSplitter(int nCount) Hs.5@l  
{ d\ 7OtM  
nSplitter = nCount; DQN"85AIZ  
} .,p@ee$q  
} 'A/{7*,  
Co<F<eXe  
#@M'*X_%}K  
/* V8%( h[  
**Utility.java Zqg AgN@  
*/ bwjLMWEVq  
package NetFox; t/x]vCP,2D  
90Z4saSUw  
y8di-d3_  
public class Utility { ;ejtP #$  
j{%'A  
S }G3ha  
public Utility() F B&l|#e  
{ bFIv}c+;  
j4D`Xq2 X  
Zr!CT5C5  
} te3\MSv;O  
y2x)<.cDP  
//线程睡眠 _cc9+o  
public static void sleep(int nSecond) wqQrby<  
{ \z-OJ1[F  
try{ 5[+E?4,&  
Thread.sleep(nSecond); x@VZJrQQ  
} hQJ-  ~  
catch(Exception e) 2\xEMec  
{ tjDCfJx*  
e.printStackTrace (); w}(Ht_6q{  
} &K,rNH'R  
} Wl>$<D4mO[  
9>L{K   
//日志 KSl@V>!_  
public static void log(String sMsg) yuB\Z/  
{ 8&y3oxA,  
System.err.println(sMsg); ^ G>/;mZ  
} =/^{Pn  
FPuF1@K  
u6p nO  
public static void log(int sMsg) V34]5  
{ 1d~cR  
System.err.println(sMsg); }zwHUf9q1  
} 6:Zd,N=  
} l$!g# ?w  
oIY@xuj  
ca!x{,Cvnj  
/* x4S0C[k  
**TestMethod.java l`<u\],  
*/ 0o&c8?@j  
package NetFox; - z"D_5  
l*4_  
CEb al\R  
public class TestMethod { @I0[B<,:G  
[yfi:|n1  
qRA ,-N  
public TestMethod() xcu:'7'K[  
{ ///xx/weblogic60b2_win.exe 0VlB7oF  
try{ y{uN+QS  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); x5nw/''[2  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f5|Ew&1EP  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1ml{oqNj  
fileFetch.start(); bp(X\:zAy  
} 4>8'.8S   
catch(Exception e){e.printStackTrace ();} tv7A&Z)Rh  
75#&hi/~  
j[YO1q*  
} ' +[fJ>Le  
J@ pCF@'  
3%SwCYd  
public static void main(String[] args) T,Zfz9{n  
{ g:>Mooxzi  
new TestMethod(); U6R~aRJ;  
} i_qR&X  
} R4g% $}  
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