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http断点续传简单实现(java)

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/* W KQ^NEqr3  
**SiteFileFetch.java !ds"9w  
*/ 5(Cl1Yse=r  
package NetFox; 8a &:6Zuo  
import java.io.*; Zvhsyz|  
import java.net.*; JBD7h5|Lc  
UN7EF/!Zz  
zUDg&-J3  
public class SiteFileFetch extends Thread { !*/*8re  
Nw:GCf-L  
yTyj'-4  
SiteInfoBean siteInfoBean = null; //文件信息Bean cO-7ke  
long[] nStartPos; //开始位置 ".f ;+wH  
long[] nEndPos; //结束位置 xpNH?#&  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 iF*:d  
long nFileLength; //文件长度 Om\o#{D  
boolean bFirst = true; //是否第一次取文件 ylUb9KusOx  
boolean bStop = false; //停止标志 cy*?&~;  
File tmpFile; //文件下载的临时信息 *EI6dD"  
DataOutputStream output; //输出到文件的输出流 5 VRYO"D:  
/xG*,YL/q  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) s J\BF  
public SiteFileFetch(SiteInfoBean bean) throws IOException HPpR.  
{ SEORSS  
siteInfoBean = bean; |VKK#J/  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); C#QpQg2  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); rI{=WPI&WU  
if(tmpFile.exists ()) "B8Q:  
{ z^KJ*E  
bFirst = false; $JSL-NkE  
read_nPos(); w;D+y*2  
} FK6[>(QO  
else PEN \-*Pv  
{ bf0+DvIB  
nStartPos = new long[bean.getNSplitter()]; )Z[ft  
nEndPos = new long[bean.getNSplitter()]; 9K/HO!z  
} m2 -Sx  
J2d.f}-  
s.EI`*xylY  
yH7F''O7  
} -VZ-<\uH  
X$%'  
XV!6dh!  
public void run() }{M#EP8q+  
{ -HQQw$  
//获得文件长度 z,|r*\dw  
//分割文件 TP VVck-T8  
//实例FileSplitterFetch B! rTD5a  
//启动FileSplitterFetch线程 [vge56h  
//等待子线程返回 U -Y03  
try{ AUeu1(  
if(bFirst) rMXN[,|v  
{ 6Vww;1 J  
nFileLength = getFileSize(); <wZQc  
if(nFileLength == -1) QS0:@.}$E)  
{ g"Ljm7  
System.err.println("File Length is not known!"); J5*tJoCYS  
} ckV`OaRw4  
else if(nFileLength == -2) z25lZI" X`  
{ %?LOs H   
System.err.println("File is not access!"); aGK?x1_  
} sfLMk E  
else 4f@o mAM  
{ INUG*JC6  
for(int i=0;i<nStartPos.length;i++) =b38(\  
{ K )[]fm  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); "ZHW2l Mf  
} |}2 3>l7  
for(int i=0;i<nEndPos.length-1;i++) `(T,+T4C5k  
{ d#6`&MR  
nEndPos = nStartPos[i+1]; a5 *2h{i  
} t c[n&X  
nEndPos[nEndPos.length-1] = nFileLength; c?P?yIz6p  
} )64@2 ~4y  
} BeCWa>54i  
.id)VF-l  
NxSu 3e~PS  
//启动子线程 +U_=*"@|  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; * +'x~a  
for(int i=0;i<nStartPos.length;i++) Ny_lrfh)[  
{ Z:ni$7<.  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1[kMOp  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nYWvTvZ  
nStartPos,nEndPos,i); Z -,J)gW  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KiRUvWqa  
fileSplitterFetch.start(); ]'5;|xc9$/  
} _C.BFE _p  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^Y<|F!0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FSUttg"  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qs|mj}?  
nEndPos = " + nFileLength); . 7zK@6i  
// fileSplitterFetch[nPos.length-1].start(); |M8WyW  
A"`foI$0  
%cCs?ic  
//等待子线程结束 "8'@3$>R=  
//int count = 0; 3VuW#m#j  
//是否结束while循环 np%\&CVhN  
boolean breakWhile = false; y+!+ D[x  
JBZUv  
*o-.6OxZ$  
while(!bStop) gWrgnlq  
{ RZ6xdq}>  
write_nPos(); 6Ztq  
Utility.sleep(500); )Y]{HQd  
breakWhile = true; !(q sD+  
ub7zA!%  
Q s.pGi0W  
for(int i=0;i<nStartPos.length;i++) [(o7$i29|%  
{ zR `EU,  
if(!fileSplitterFetch.bDownOver) ~)qtply  
{ qud\K+  
breakWhile = false; PN0VQ/..  
break; 1J6,]M  
} .P.z B}0=  
} tyfTU5"x  
if(breakWhile) ygeDcnvR]  
break; U`,0]"Qk  
\(VTt|}By$  
I6j$X6u  
//count++; ,QC{3i~  
//if(count>4) ^F2b hXE  
// siteStop(); 3k|oK'l  
} I<Ksi~*i  
:gerQz4R8  
o[v\|Q`d  
System.err.println("文件下载结束!"); Z-8Yd6 4  
} ? 9! Z<H  
catch(Exception e){e.printStackTrace ();} IGS1|  
} rm4.aO~-F  
wUiys/ OVM  
3l[Mc Z  
//获得文件长度 Au{<hQ =  
public long getFileSize() ^M%uV  
{ %@;6^=  
int nFileLength = -1; 0`)iIz  
try{ @S|jC2^+h  
URL url = new URL(siteInfoBean.getSSiteURL()); I#m-g-J  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y7#-Fra0W  
httpConnection.setRequestProperty("User-Agent","NetFox"); U7doU'V/  
i:rFQ8 I  
90|7ArM_[  
int responseCode=httpConnection.getResponseCode(); 6lk l7zm  
if(responseCode>=400) !_+8A/  
{ 8~90 30>Q  
processErrorCode(responseCode); BYTnrPA&Z;  
return -2; //-2 represent access is error t| 9 GS|  
} %7#-%{  
CNQC^d\ h  
TT50(_8  
String sHeader; XW -2~?$  
X/z6"*(|/  
zUkN 0  
for(int i=1;;i++) JoRT&rkd  
{ bV edFm  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?pYKZg /c  
//Utility.log(in.readLine()); U7!.,kR-  
sHeader=httpConnection.getHeaderFieldKey(i); !O.[PH(,*  
if(sHeader!=null) )x}l3\s  
{ *<E]E?  
if(sHeader.equals("Content-Length")) hX`hs- *qM  
{ o;W`4S^  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \Y|~2Ls8tu  
break; 'eo KZX+  
} 4(Ov1a>  
} .!1S[  
else 5k6mmiaKk  
break; gXonF'  
} R)F;py8)I  
} #VB')^d<U  
catch(IOException e){e.printStackTrace ();} AK= h[2(  
catch(Exception e){e.printStackTrace ();} [,K.*ZQi  
CT KG9 T  
0{[m%eSK'  
Utility.log(nFileLength); %1.]c6U  
JYrY[',u  
[q_`X~3  
return nFileLength; fV v.@HL{  
}  )LJnLo+  
hq:&wN 7Q  
s@z}YH  
//保存下载信息(文件指针位置) ~7$&WzD  
private void write_nPos() Nc :({@I  
{ ({-GOw46  
try{ ! iptT(2  
output = new DataOutputStream(new FileOutputStream(tmpFile)); %V1Z~HC  
output.writeInt(nStartPos.length); yz-,)GB6  
for(int i=0;i<nStartPos.length;i++) b B  x?  
{ :Xn7Ha[f  
// output.writeLong(nPos); !ALKSiSl  
output.writeLong(fileSplitterFetch.nStartPos); Nru7(ag1~  
output.writeLong(fileSplitterFetch.nEndPos); qw7@(R'"  
} DUL4noq{  
output.close(); f'<Q.Vh<  
} Mmo6MZ^  
catch(IOException e){e.printStackTrace ();} Q\GDrdA  
catch(Exception e){e.printStackTrace ();} yfj K2  
} &K43x&mFF  
y.=/J8->  
]c<qM_HWg  
//读取保存的下载信息(文件指针位置) `%E8-]{uS  
private void read_nPos() X=6y_^  
{ -D N8Yb  
try{ i]=&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KjFK/Og.  
int nCount = input.readInt(); Ti2Ls5H}  
nStartPos = new long[nCount]; `} m Q  
nEndPos = new long[nCount]; JXixYwm  
for(int i=0;i<nStartPos.length;i++) ~`GhS<D  
{ ik"sq}u_]E  
nStartPos = input.readLong(); l" q1?kaVg  
nEndPos = input.readLong(); /erN;Oo%<  
} ed!:/+3e/  
input.close(); zF@o2<cD@  
} <W`#gn0b6  
catch(IOException e){e.printStackTrace ();} ?9HhG?_x  
catch(Exception e){e.printStackTrace ();} RP 2_l$  
} ari7iF ~j  
^A][)*SZ  
QDTBWM%  
private void processErrorCode(int nErrorCode) 8>7RxSF  
{ kW`r=u  
System.err.println("Error Code : " + nErrorCode); OFGsjYLw  
} 5jgdbHog]  
j}BHj.YuP  
uk9g<<3T  
//停止文件下载 Zes+/.sA}]  
public void siteStop() xy8#2  
{ ~ ^>417>  
bStop = true; RQkyCAGx  
for(int i=0;i<nStartPos.length;i++) $55U+)C<  
fileSplitterFetch.splitterStop(); xrqv@/kJ  
jSOS}!=  
[3W*9j  
} ;uqx@sx ;  
} `:wvh(  
//负责部分文件的抓取 sow d`I~  
**FileSplitterFetch.java :^'O}2NP  
*/ R#n%cXc|  
package NetFox; R*zO dxY  
!j1[$% =#  
tp:\j@dB  
import java.io.*; Um)>2|rp}  
import java.net.*; ? b[n|^wS  
C{Asp  
sBK <zR  
public class FileSplitterFetch extends Thread { 7 uMd ZpD  
YB)3X[R+0  
tu>{  
String sURL; //File URL iB1i/l  
long nStartPos; //File Snippet Start Position nRb^<cZf  
long nEndPos; //File Snippet End Position c=[q(|+O!  
int nThreadID; //Thread's ID jJ3zF3Id  
boolean bDownOver = false; //Downing is over _Cy:]2o  
boolean bStop = false; //Stop identical v)f7};"z   
FileAccessI fileAccessI = null; //File Access interface .fzu"XAPu  
cBYfXI0`  
'r} zY-FM`  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3L _I[T$s  
{ TwvAj#j  
this.sURL = sURL; LF?P> 1%-  
this.nStartPos = nStart; ~:lKS;PRuK  
this.nEndPos = nEnd; o5Y2vmz?9  
nThreadID = id; F52B~@ .  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T;\^#1  
} C}?0`!Cc%  
~AG$5!  
]h!`IX  
public void run() [4+q+  
{ 3+xy4 G@L  
while(nStartPos < nEndPos && !bStop) fd8!KO  
{ VW@ x=m  
S2C]?6cTq  
g,]@4|  
try{ "PH6e bm  
URL url = new URL(sURL); 6QZ5|T ]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q (+ZwaV@  
httpConnection.setRequestProperty("User-Agent","NetFox"); C+F*690h  
String sProperty = "bytes="+nStartPos+"-"; !umEyd@ "  
httpConnection.setRequestProperty("RANGE",sProperty); m"-[".-l-  
Utility.log(sProperty); [9mL $;M W  
@!Hr|k|  
gVU1Y6.  
InputStream input = httpConnection.getInputStream(); h:/1X' 3d  
//logResponseHead(httpConnection); i2Jq|9,g  
,>LRa  
la$%H<,7  
byte[] b = new byte[1024]; MS<SAD>w  
int nRead; *Q}[ ]g  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (LJ@S eM;  
{ Gzt=u"FV  
nStartPos += fileAccessI.write(b,0,nRead); ;\y ;  
//if(nThreadID == 1) w7-WUvxl  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XD-^w_  
} ] c}91  
JmOW~W  
5IqQ|/m<6  
Utility.log("Thread " + nThreadID + " is over!"); fT Y/4(  
bDownOver = true; !q4x~G0d  
//nPos = fileAccessI.write (b,0,nRead); % do1i W  
} h4fLl3%H  
catch(Exception e){e.printStackTrace ();} pKJK9@Ad  
} LD(C\  
} DFe;4BdC  
TSL9ax4j  
7\/5r.  
//打印回应的头信息 znZ7*S >6\  
public void logResponseHead(HttpURLConnection con) ~# 7wdP  
{ uCzii o`S  
for(int i=1;;i++) Y:x/!-  
{ V*65b(q)  
String header=con.getHeaderFieldKey(i); zuL7%qyv  
if(header!=null) 0y %L-:/c|  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *]s&8/Gmb  
Utility.log(header+" : "+con.getHeaderField(header)); ';RI7)<  
else x:5dC I  
break; )QY![&k}1z  
} tSv0" L  
} +=c am/A  
_$/ +D:K  
IS]{}Y\3H  
public void splitterStop() gbOCR1PBg  
{ \gccQig1CJ  
bStop = true; mog9jw  
} b>cafu  
/N^~U&7  
'pP-rdx  
} w@]jpH;WX  
eZF'Ck y  
K]N~~*`%`  
/* cfoYnM  
**FileAccess.java B} *V%}:)  
*//文件访问(定位,写) - G ?%QG`v  
package NetFox; A['uD<4b  
import java.io.*; y7zkAXhJ  
IG.f=+<0  
ValS8V*N1  
public class FileAccessI implements Serializable{  pbB2wt  
\~"#ld(x7  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6w#nkF  
RandomAccessFile oSavedFile; [}""@?  
long nPos; ,5-Zb3\  
?ow'^X-  
PM~*|(fA  
public FileAccessI() throws IOException aIGn9:\  
{ _J"mR]I+  
this("",0); &?a.mh/8[[  
} QjukK6#W  
mf*Nr0L;J  
R40W'N 1%q  
public FileAccessI(String sName,long nPos) throws IOException wz@FrRP=  
{ Y"> 4Qx4W  
oSavedFile = new RandomAccessFile(sName,"rw"); Hbr^vYs5  
this.nPos = nPos; ~8Sqa%F>  
oSavedFile.seek(nPos); mC(u2  
} hhq$g{+[  
nN{dORJlx  
1 Nk1MGV  
public synchronized int write(byte[] b,int nStart,int nLen) ;?im(9h"v!  
{ aR(E7mXQ  
int n = -1; &d 3HB=x  
try{ &|z544  
oSavedFile.write(b,nStart,nLen); ag]*DsBt  
n = nLen; \8_V(lU   
} ABWb>EZ8  
catch(IOException e) J'7 y   
{ b:x7)$(  
e.printStackTrace (); PHkDb/HIx|  
} A#:8X1w  
*98Ti|  
{( HxG4~  
return n; }=pOiILvD  
} ]I XAucI]  
FuMq|S  
RdkU2Y}V  
} F^TAd  
-M`D >  
jlRS:$|R0  
/* 1E^{B8cm  
**SiteInfoBean.java QJM(UfHUD  
*/ =|# w.(3y  
package NetFox; M 5rwoyn  
8 DL hk  
:xN8R^(  
public class SiteInfoBean { u S(@?m$  
;x RjQR  
._K$0U!  
private String sSiteURL; //Site's URL 6 <r2*`  
private String sFilePath; //Saved File's Path X o_] v  
private String sFileName; //Saved File's Name 67ZYtA|t  
private int nSplitter; //Count of Splited Downloading File <!hpfTz*  
Ix4jof6(  
7n<#y;wo  
public SiteInfoBean() $OT}`Te~  
{//nSplitter的缺省值为5 q1<Fg.-r  
//default value of nSplitter is 5 FB.!`%{  
this("","","",5); q'fPNQg  
} $KH@,;Xz  
^VC7C~NZ!M  
8t--#sDy{0  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [ArO$X3\  
{ A@\qoS[  
sSiteURL= sURL; VEr 6uvB  
sFilePath = sPath; qU}lGf!dVn  
sFileName = sName; #Ul4&QVeg  
this.nSplitter = nSpiltter; {4o\S  
HUD7{6}4  
Sn+FV+D  
} olHH9R9:  
rSzQUn<  
X!2.IsIS8  
public String getSSiteURL() KuU3DTS85Z  
{ QR|XV%$  
return sSiteURL; 9PUa?Bc`=  
} A-X  
ef^Cc)S-Q  
P}+2>EU  
public void setSSiteURL(String value) -??!@R7V  
{ Z={D0`  
sSiteURL = value; @*bvMEE  
} d?Ia#K9 3G  
0,;E.Py?.  
g?w2J6Z.`J  
public String getSFilePath() e~tr^$/(  
{ rsd2v9  
return sFilePath; }g%KvYB_  
} kQqBHA  
4!NfQk>X  
bnA T,v{  
public void setSFilePath(String value) Jslk  
{ j` [#Ij  
sFilePath = value; deR$  
} "$`wk  
Y\+(rC27  
^zBjG/'7  
public String getSFileName() MLkL.1eGSb  
{ >cGh|_9  
return sFileName; J- @o@!o  
} ?/o2#iJx  
{m?K2]](  
K> c8r8!  
public void setSFileName(String value) Z/XM `Cy  
{ (#f m (@T  
sFileName = value; r78u=r  
} }:,o Y<  
"R@$Wu53|  
>reaIBT  
public int getNSplitter() B FzcoBu-  
{ $[HcHnf  
return nSplitter; p?J~'  
} t(Q&H!~e   
Verbmeg&n  
GnSgO-$"  
public void setNSplitter(int nCount) { r< (t#  
{ W\ 1bE(AwZ  
nSplitter = nCount; o<C]+Nt,@  
} |_hioMVz  
}  ~ LJ>WA  
!=~s/{$PE  
.}L-c>o"o  
/* &cv@Kihq(  
**Utility.java 0U>t>&,"  
*/ C8bGae(  
package NetFox; Q1O_CC}  
`:-@E2  
3/A!_Uc(  
public class Utility { Lo$Z>u4(c  
3*X, {%  
>|UrxJ7  
public Utility() * zw R=  
{ cJ7{4YK_#/  
a in#_H  
@);!x41f  
} 73^ T*  
imJ[:E  
//线程睡眠 v&[X&Hu[  
public static void sleep(int nSecond) [9db=$v8$  
{ gL[1wM%?  
try{ XEvGhy#  
Thread.sleep(nSecond); <WQ<<s@#pb  
} avHD'zU}N  
catch(Exception e) 2yEO=SN,(  
{ Vid{6?7kh  
e.printStackTrace (); tdw\Di#m  
}  Gh)sw72  
} -H ac^4uF  
U- *8%>Qp  
//日志 xzMeKC `  
public static void log(String sMsg) D^N#E>,  
{ BST7y4R)BS  
System.err.println(sMsg); Q}=W>|aE.  
} lJGqR0:r+  
:XPC0^4s  
@aqd'O  
public static void log(int sMsg) uK4'n+_>\  
{ LEn=dU  
System.err.println(sMsg); O$<%z[  
} aUIc=Z  
} #TW>'l F  
<y\ Z#z  
Y?&DEKFbD  
/* +s/N@]5nW  
**TestMethod.java (A]m=  
*/ k+7M|t.?4  
package NetFox; R$T[%AGZ.  
Wd^F%)(  
Bah.\ZsYQP  
public class TestMethod {  ^ :  
[U3D`V$xD  
-hU>1ux&V  
public TestMethod() @o3R`ZgC]\  
{ ///xx/weblogic60b2_win.exe c:@OX[##  
try{ ]9KQP-p'  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aCYm$6LmA  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w ~L\Ebg  
SiteFileFetch fileFetch = new SiteFileFetch(bean); JK:mQ_  
fileFetch.start(); mNnw G);$  
} \AtwO  
catch(Exception e){e.printStackTrace ();} lEYT{  
<<W.x)#:  
MWn L#!  
} mSk :7ozZ  
v]`A_)[  
\:_.N8"  
public static void main(String[] args) Y#SmZ*zok  
{ 'wB Huq  
new TestMethod(); K9I,Q$&xX  
} pw<q?q%  
} [oU+b(  
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