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http断点续传简单实现(java)

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/* Mz;KXP  
**SiteFileFetch.java w NMA)S  
*/ UGP&&A#T-  
package NetFox; D 75;Y;E  
import java.io.*; ozl>Au  
import java.net.*; YOUX  
$v=(`=  
wif1|!aL  
public class SiteFileFetch extends Thread { y/"CWD/i  
Q!h+1fb  
B+2.:Zn6  
SiteInfoBean siteInfoBean = null; //文件信息Bean $I9U.~*  
long[] nStartPos; //开始位置 (Vt5@25JW  
long[] nEndPos; //结束位置 Us3zvpy)o  
FileSplitterFetch[] fileSplitterFetch; //子线程对象  }S}%4c>  
long nFileLength; //文件长度 fdgjTX  
boolean bFirst = true; //是否第一次取文件 @QDpw1;V'  
boolean bStop = false; //停止标志 h@Ix9!?+  
File tmpFile; //文件下载的临时信息 =27ZY Z  
DataOutputStream output; //输出到文件的输出流 a4",BDx  
m[Qr>="  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Kj:'Ei7  
public SiteFileFetch(SiteInfoBean bean) throws IOException X rut[)H  
{ 6ciA|J'MR  
siteInfoBean = bean; sfsK[c5bm  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); /Ur]U w  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); T^Hq 5Oy  
if(tmpFile.exists ()) rWJKK  
{ }p*WH$!~  
bFirst = false; 8cj}9}k  
read_nPos(); 7+rroCr"  
} MF +F8h>/  
else TIno"tc3  
{ ^vTp.7o~5  
nStartPos = new long[bean.getNSplitter()]; F`o"t]AD-a  
nEndPos = new long[bean.getNSplitter()]; 'N/u< `)  
} TU9$5l/;g  
}L>0}H  
+ ,rl\|J%  
][>-r&V  
} "}:SXAZ5`  
xxpzz(S ]A  
[\=1|t5n~  
public void run() COA>y?  
{ 'Ge8l%p  
//获得文件长度  r^,"OM]  
//分割文件 l@>@2CB  
//实例FileSplitterFetch Oo9'  
//启动FileSplitterFetch线程 _: !7M ^IU  
//等待子线程返回 ~P"o_b6,k  
try{ c>wn e\(5H  
if(bFirst)  x(A6RRh  
{ H1$n6J  
nFileLength = getFileSize(); 5]2 p>%G  
if(nFileLength == -1) \ F)}brPc  
{ ra^"Vr  
System.err.println("File Length is not known!"); RT[ E$H  
} SxL/]jWR7  
else if(nFileLength == -2) -6# _t  
{ |q Pu*vR  
System.err.println("File is not access!"); z]!w@:  
} [$Jsel<T=  
else t_\&LMD  
{ 9yj'->dL  
for(int i=0;i<nStartPos.length;i++) 8*&YQId~  
{ WpC9(AX5g  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 5X:3'*  
} rW`l1yi*$  
for(int i=0;i<nEndPos.length-1;i++) 2fP;>0?  
{ CM)V^k*  
nEndPos = nStartPos[i+1]; c9+yU~(  
} s $ ?;C  
nEndPos[nEndPos.length-1] = nFileLength; U"a7myB+jX  
} ,?wxW  
} Y.% Vvg4z3  
=:\5*  
8qoA5fW>  
//启动子线程 E|W7IgS  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3Qu-X\  
for(int i=0;i<nStartPos.length;i++) KIY9?B=+  
{ d"thM  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DkW^gt  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P[r$KGz  
nStartPos,nEndPos,i); IaO*{1re  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \xmDkWzE  
fileSplitterFetch.start(); kR{$&cE^  
} R0-Y2v  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `)Y 5L}c=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Jv!f6*&<  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o Va[  
nEndPos = " + nFileLength); OXbC\^qo@  
// fileSplitterFetch[nPos.length-1].start(); 3A\Z ]L  
mB%m<Zo\U  
GK#D R/OM  
//等待子线程结束 Is9.A_0h  
//int count = 0; A>\3FeU>UC  
//是否结束while循环 " +hUt  
boolean breakWhile = false; gl!ht@;>ak  
\!*F:v0g^  
%1)JRc  
while(!bStop) Hro)m"  
{ 5[~ C!t;  
write_nPos(); UU ' 9  
Utility.sleep(500); ^}lL@Bd|  
breakWhile = true; kH=qJ3Z  
.ZM0cwF  
#;UoZJ B  
for(int i=0;i<nStartPos.length;i++) ,2P /[ :  
{ &uI33=   
if(!fileSplitterFetch.bDownOver) qipS`:TER  
{ >E WK cocM  
breakWhile = false; #r]GnC,  
break; |C>\k u*  
} D2zqDo<+;  
} R9UC0D:-x  
if(breakWhile) ^[v>B@p*{  
break; oUB9)C~  
`R*!GHro  
!ED,'d%J  
//count++; @Y#TWt#  
//if(count>4) ]Nue1xV_  
// siteStop(); f|2QI ~R  
} ?S.LGc  
?yA 2N;  
 5e2yJ R  
System.err.println("文件下载结束!"); mOb@w/f  
} Qd}h:U^  
catch(Exception e){e.printStackTrace ();} yaAg!mW  
} V_KHVul  
sO)!}#,   
0p'g+ 2  
//获得文件长度 p&HkR^.S  
public long getFileSize() }mS+%w"j  
{ <O{G&  
int nFileLength = -1; (dym*_J  
try{ $-gRD|oY  
URL url = new URL(siteInfoBean.getSSiteURL()); "rw'mogRL  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); / q^_ 'Lp  
httpConnection.setRequestProperty("User-Agent","NetFox"); pH0MVu(W  
M ED_#OS  
N Q }5'  
int responseCode=httpConnection.getResponseCode(); W;8}`k  
if(responseCode>=400) QtOT'<2t]  
{ q{7+N1 "  
processErrorCode(responseCode); ^1XnnQa  
return -2; //-2 represent access is error (- {.T  
} [O6JVXO>  
&l W~ot1,  
xic&m5j m  
String sHeader; #}8gHI-9%  
K Z0%J5  
jDW$}^ 6  
for(int i=1;;i++) > Cx;h=  
{ a<Ps6'  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wE_#b\$=b  
//Utility.log(in.readLine()); gR k+KGKn<  
sHeader=httpConnection.getHeaderFieldKey(i); }do=lm?/  
if(sHeader!=null) @FuX^Q.[  
{ HE3x0H}o>  
if(sHeader.equals("Content-Length")) Y^ ,G} &p  
{ h>n<5{zqM  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +Z/aG k;  
break; T?8N$J  
} m# I  
} u]t#Vf-$u  
else 9 icy&'  
break; 9jrlB0  
} h?&S*)1  
} 3d>xg%?  
catch(IOException e){e.printStackTrace ();} (s!cd]Qa.  
catch(Exception e){e.printStackTrace ();} 3HB(rTw  
zY\MzhkX,  
YnX6U 1/^  
Utility.log(nFileLength); O%busM$P)/  
%2rUJaOgy$  
sTF Ru  
return nFileLength; wfBf&Z0{  
} ~@EBW3>~5  
-wn(J5NnR  
F$H^W@<w  
//保存下载信息(文件指针位置) O.wk*m!9  
private void write_nPos() w_^g-P[o-  
{ l|~SVk|  
try{ Z/= HQ8  
output = new DataOutputStream(new FileOutputStream(tmpFile)); HXRK<6k$  
output.writeInt(nStartPos.length); .5?Md  
for(int i=0;i<nStartPos.length;i++) #wZBWTj.  
{ p+|(lrYC  
// output.writeLong(nPos); 1N\-Ku  
output.writeLong(fileSplitterFetch.nStartPos); bY7~b/  
output.writeLong(fileSplitterFetch.nEndPos); YNWAef4  
} +#0,2 wR#  
output.close(); / ,#&Htk  
} BX6]d:S  
catch(IOException e){e.printStackTrace ();} 7Ys\=W1  
catch(Exception e){e.printStackTrace ();} 5nJmabw3  
} 334tg'2]  
V/i7Zh#2:  
+b6kU{  
//读取保存的下载信息(文件指针位置) !)TO2?,^  
private void read_nPos() Na2n4x!  
{ (.54`[2+L  
try{ 5Rec~&v  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Sej\Gt  
int nCount = input.readInt(); E;C=V2#>[  
nStartPos = new long[nCount]; /J0ctJ2k  
nEndPos = new long[nCount]; Fl&Z}&5p  
for(int i=0;i<nStartPos.length;i++) ^\zf8kPti  
{ ti^msC8e  
nStartPos = input.readLong(); \LZVazXD  
nEndPos = input.readLong(); - d(RK_  
} SRf .8j  
input.close(); G%RhNwm  
} mBZg(TY  
catch(IOException e){e.printStackTrace ();} |Y\BI^  
catch(Exception e){e.printStackTrace ();} 3"J85V%h]n  
} l\{{iAC]I  
-?&s6XA%#  
5 NdIbC  
private void processErrorCode(int nErrorCode) iH""dtO  
{ A('_.J=  
System.err.println("Error Code : " + nErrorCode); O*zF` 9  
} fA>FU/r  
#'jd.'>  
KQ(7%W  
//停止文件下载 1P+Te,I  
public void siteStop() i VIpe  
{ b#[7A  
bStop = true; IHlTp0?  
for(int i=0;i<nStartPos.length;i++) lwuslt*E/  
fileSplitterFetch.splitterStop(); \a}W{e=FNT  
`;fk,\8t%  
=/jCDY  
} z4 yV1  
} c_YP#U  
//负责部分文件的抓取 5U+a{oA  
**FileSplitterFetch.java XKq}^M&gy  
*/ <X,0\U!lL  
package NetFox; 8~")9w  
R7xEE7p  
nd/.]"  
import java.io.*; dNMz(~A[Y  
import java.net.*; Y"&1jud4xl  
O A9G] 8k  
*(sUz?t  
public class FileSplitterFetch extends Thread { }yW*vy6`  
=`MU*Arcs[  
v{dvB:KP5X  
String sURL; //File URL pl.K*9+  
long nStartPos; //File Snippet Start Position QirS=H+~  
long nEndPos; //File Snippet End Position ?pJUbZ#J  
int nThreadID; //Thread's ID ;jgJI~3l  
boolean bDownOver = false; //Downing is over zU1[+JJY"{  
boolean bStop = false; //Stop identical @ s2<y@  
FileAccessI fileAccessI = null; //File Access interface M:? :EJ  
f^63<gqY  
S=bdue  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^Gs=U[**  
{ ?nya;Z-~Hc  
this.sURL = sURL; .:)nG(7f<  
this.nStartPos = nStart; *3>$ f.QU  
this.nEndPos = nEnd; y! lEGA7  
nThreadID = id; BRg(h3 ED  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^cy.iolt  
} 'U" ub2j  
(?7=$z!h  
gZD,#D.hR  
public void run() dUg| {l  
{ GcL:plz  
while(nStartPos < nEndPos && !bStop) {tlt5p!4  
{ <!r0[bKz@  
yj48GQP]  
&CEZ+\bA  
try{ "}jY;d#n  
URL url = new URL(sURL); =(x W7Pt~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z sZP\  
httpConnection.setRequestProperty("User-Agent","NetFox"); $stBB  
String sProperty = "bytes="+nStartPos+"-"; u(!@6%?-  
httpConnection.setRequestProperty("RANGE",sProperty); J^R#  
Utility.log(sProperty); L,B#%t  
aF~ 0\XC  
{IlX@qWr  
InputStream input = httpConnection.getInputStream(); `1eGsd,f  
//logResponseHead(httpConnection); z` :uvEX0  
JWuF ?<+k  
!VJ5(b  
byte[] b = new byte[1024]; 9<ev]XaSl  
int nRead; rprtp5Cg  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xxN=,p  
{ wwtk6;8@  
nStartPos += fileAccessI.write(b,0,nRead); mz~aSbb|  
//if(nThreadID == 1) 0DFxVH_xN  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mar BVFz~  
} eaI!}#>R +  
P{-f./(JD  
UF)4K3X  
Utility.log("Thread " + nThreadID + " is over!"); #l!Sz247  
bDownOver = true; KF#,Q  
//nPos = fileAccessI.write (b,0,nRead); 3'H 1T  
} y~cDWD <h  
catch(Exception e){e.printStackTrace ();} *Q@%< R  
} ^mu?V-4  
} >lRa},5(  
_k,/t10  
^\X-eeA  
//打印回应的头信息 Yb<t~jm  
public void logResponseHead(HttpURLConnection con) I<'wZJRRa  
{ Y GZX}-  
for(int i=1;;i++) FD&"k=p+X  
{ '01ifA^  
String header=con.getHeaderFieldKey(i); ,KMt9 <  
if(header!=null) %S<0l@=5`l  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _Co*"hl>2  
Utility.log(header+" : "+con.getHeaderField(header)); +s}"&IV%  
else Q599@5aS  
break; m2YsE  j7  
} Fq!_VF^r  
} w El-  
[)dIt@Y&j  
?E(X>tH  
public void splitterStop() `u R`O9)e  
{ aG]^8`~>'  
bStop = true; KZ%us6  
} ( ;^>G[  
GQJ4d-w  
s$(%?,yf2  
} r:g_mMvB  
zUNUH^Il  
:<k (y?GB  
/* nHH FHnFf  
**FileAccess.java 9$U4x|n  
*//文件访问(定位,写) W}2!~ep!  
package NetFox; 6O.kKhk  
import java.io.*; (9TSH3f?  
Z h9D^ I  
Iu~<Y(8^q#  
public class FileAccessI implements Serializable{ 5o>*a>27,A  
vF pKkS343  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7jQVm{{.  
RandomAccessFile oSavedFile; #qR6TM&;  
long nPos; 5XzsqeG|  
A+frKoi  
ZZHzC+O#^  
public FileAccessI() throws IOException Iz'Et'w8!  
{ sKsMF:|OT  
this("",0); @iXBy:@  
} a j$& 9][  
8O(L;&h  
tLN^k;w  
public FileAccessI(String sName,long nPos) throws IOException 3 =c#LUA`  
{ ;m>/tD%  
oSavedFile = new RandomAccessFile(sName,"rw"); wfEL .h  
this.nPos = nPos; ~e]B[>PT  
oSavedFile.seek(nPos); }&v-<qC^  
} HwZl"!;Mry  
HC1<zW[  
' (XB|5  
public synchronized int write(byte[] b,int nStart,int nLen) *]h"J]  
{ 2<p@G#(  
int n = -1; k9<UDg_ Y  
try{ E i>GhvRM  
oSavedFile.write(b,nStart,nLen); WiB~sIp  
n = nLen; 6OAEAIh  
} B:0oT  
catch(IOException e) aPK:k$.  
{ :8@eon}  
e.printStackTrace (); j (Q# NFT7  
} OI"g-+~  
~m,~;  
h(~/JW[  
return n; )"hd"  
} -y|']I^ &  
jAue+ tB  
%#~wFW|]x  
} CDXN%~0h  
T0"nzukd  
>3B {sn}  
/* 7CSz  
**SiteInfoBean.java izGU&VeB  
*/ }$L1A   
package NetFox; Q _!tn*  
2#3`[+g<n  
<H-kR\HF  
public class SiteInfoBean { C4`&_yoP4-  
ai1;v@1  
G3+e5/0  
private String sSiteURL; //Site's URL 89GW!  
private String sFilePath; //Saved File's Path S;gy:n!t  
private String sFileName; //Saved File's Name QKx(S=4jQ  
private int nSplitter; //Count of Splited Downloading File o#1Ta7Ro  
&"gX 7cK8  
bc~$"  
public SiteInfoBean() 9&Un|cr  
{//nSplitter的缺省值为5 cn/&QA"  
//default value of nSplitter is 5 ~6Fh,S1?  
this("","","",5); 8-7Ml3G*  
} EW vhT]<0  
+HRtuRv0T  
=q)+_@24>d  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (Cq 38~mR  
{ ?wv3HN  
sSiteURL= sURL; Vn:v{-i  
sFilePath = sPath; \9tJ/~   
sFileName = sName; +;,J0,Yn  
this.nSplitter = nSpiltter; WQ.{Ag?1  
t?)]xS)  
8IWT;%  
} 1@ &J"*  
dmv0hof  
&08dW9H  
public String getSSiteURL() Lb<IEy77\  
{ x|Pz24yP9  
return sSiteURL; jPZ+~:m+  
} n7~4*B  
((#BU=0iK  
NB'G{),)Z  
public void setSSiteURL(String value) nvLdgu4P>  
{ Qjnh;uBO  
sSiteURL = value; IA Ma  
} -AD` (b7q  
'%ZKvZ-  
_Li.}g@Bd  
public String getSFilePath() He4HI Z  
{ qzA_ ~=g  
return sFilePath; $ kHXt]fU  
} 7t#Q8u?  
wme#8/eUk  
4guR8 elM  
public void setSFilePath(String value) t\ z@k9  
{ X(Mpg[,N"  
sFilePath = value; w/*#TDR  
} qN' 3{jiPL  
7G;1n0m-T  
ml^=y~J[  
public String getSFileName() :=+YZ|&j  
{ a3w6&e`  
return sFileName; Fq <JxamR  
} I~YV&12  
`uk=2k}&m  
GYb&'#F~t  
public void setSFileName(String value) fK]%*i_"  
{ CMbID1M3  
sFileName = value; |.yS~XFJS  
} _[(EsIqc(F  
Pw]r&)I`y[  
nsXG@CS:  
public int getNSplitter() z)v o  
{ LWhy5H;Es  
return nSplitter; [*(1~PrlO,  
} 1BW9,Xr  
jVOq/o  
?f3R+4  
public void setNSplitter(int nCount) B=%%3V)2  
{ C{nk,j L  
nSplitter = nCount; Akc |E!V  
} LH+Bu%s  
} RyukQY~<W  
3]lq#p:  
RdyKd_0`Q  
/* 0F_hXy@K  
**Utility.java sKKc_H3YSH  
*/ fH_l2b[-3@  
package NetFox; ;r6YIS4@  
;~$Q;m 1  
h@1/  
public class Utility { M[O22wFs  
)!E:  
L;vglS=l;  
public Utility() {: _*P TVk  
{ =?+w5oI0  
T95FoA  
9ei'oZ  
} !ii( 2U  
\}kR'l  
//线程睡眠 gpzFY"MS=  
public static void sleep(int nSecond) .mqMzV  
{ NX(+%EBcA  
try{ %x@bP6d[  
Thread.sleep(nSecond); Eul3 {+]  
} s 72yu}  
catch(Exception e) &FOq c  
{ /y4A?*w6  
e.printStackTrace (); "SQyy  
} NJd4( P  
} gp 11/ .  
Q7F4OS5b  
//日志 HGh)d` 8  
public static void log(String sMsg) nSQ]qH&4d  
{ Q"eqql<h#  
System.err.println(sMsg); >c Tt2v  
} 3$K[(>s  
[okV[7  
Kx,X{$Pe  
public static void log(int sMsg) s m G?y~  
{ TxN+-< f  
System.err.println(sMsg); WL'!M&h  
} dQ_'8 )  
} N M),2%<  
hSAI G  
:@E^oNKa0  
/* <?L5bhq  
**TestMethod.java EW4a@  
*/ + `'wY?  
package NetFox; CK4#ZOiaa  
jgXr2JQ<  
&dj/Dq@  
public class TestMethod { Gf.xr%mUZr  
nZL!}3@<  
+Lc+"0*gV*  
public TestMethod() 'Pn:10;  
{ ///xx/weblogic60b2_win.exe fy$CtQM  
try{ GyxLzrp  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !H c6$  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &6Lh>n(  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^b$G.h{o!E  
fileFetch.start(); Xm(#O1Vm(l  
} %t1Z!xv_  
catch(Exception e){e.printStackTrace ();} >,k2|m  
u6Ux nqNc  
#wvGS%  
} 7J$rA.tu  
(M{wkQTO  
|d6/gSiF  
public static void main(String[] args) ;O,&MR{;|n  
{ =)i^E9  
new TestMethod(); Y Kp@ n8A  
} L.K|]]u  
} a5pM~.]  
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