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http断点续传简单实现(java)

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/* wkt4vE87  
**SiteFileFetch.java +Y?Tri  
*/ 8{4'G$6  
package NetFox; !@z9n\Yj  
import java.io.*; eXl?f_9  
import java.net.*; @fd<  
#aqnj+  
/ 4Q=%n  
public class SiteFileFetch extends Thread { h[(YH ;Y  
^A ]4  
|r@;ulO  
SiteInfoBean siteInfoBean = null; //文件信息Bean O@$>'Z  
long[] nStartPos; //开始位置 "@x( 2(Y&  
long[] nEndPos; //结束位置 +wQ5m8E  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 WyV4p  
long nFileLength; //文件长度 r9f- C  
boolean bFirst = true; //是否第一次取文件 S]H[&o1o  
boolean bStop = false; //停止标志 "5JMk -2k  
File tmpFile; //文件下载的临时信息 %`~4rf"7  
DataOutputStream output; //输出到文件的输出流 >\JP X  
oIrc))j,$  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ckX8eg!f  
public SiteFileFetch(SiteInfoBean bean) throws IOException BFNO yv  
{ ,88B@a  
siteInfoBean = bean; 'M%iS4b{IM  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); }cz58%  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); /IirTmFK  
if(tmpFile.exists ()) P}6#s'07~  
{ Dk\%,[4(  
bFirst = false; )=)N9CRy  
read_nPos(); &^ERaPynd  
} jnV#Q ;  
else Gr({30"8  
{ Yyk~!G/@  
nStartPos = new long[bean.getNSplitter()]; sD3Ts;k  
nEndPos = new long[bean.getNSplitter()]; }Z <I%GT  
} 1^k}GXsWmE  
>D=X Tgqqq  
!+$qSD,%x  
h x^@aI  
} i%yKyfD  
+HE,Q6-A  
Yte*$cJ=  
public void run() ( %sf wv  
{ thPAD+u.3  
//获得文件长度 %Vo'\|  
//分割文件 9ERdjS  
//实例FileSplitterFetch 5T/+pC$e=  
//启动FileSplitterFetch线程 {Lju7'5L  
//等待子线程返回 3\2&?VAjR  
try{ ;)rhx`"n  
if(bFirst) z{R Mb  
{ &Zz&VwWR  
nFileLength = getFileSize(); 8h ol4'B  
if(nFileLength == -1) iu{y.}?  
{ @G& oUhS  
System.err.println("File Length is not known!"); GUQ3XF\  
} ]`-o\,lq  
else if(nFileLength == -2) r[E#JHw  
{ ZZi 9<g1  
System.err.println("File is not access!"); E.#JCO|(1  
} X'd\b}Bm  
else NiG&Lw*8  
{ nR%w5oe  
for(int i=0;i<nStartPos.length;i++) ?r;F'%N=  
{ ,,FhE  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); c'$y_]  
} 8?~>FLWTXZ  
for(int i=0;i<nEndPos.length-1;i++) a[t"J*0  
{ V xN!Ki=  
nEndPos = nStartPos[i+1]; i@{b+5$  
} #~Kno@  
nEndPos[nEndPos.length-1] = nFileLength; j\#)'>"  
} Jn(|.eT|  
} O-AC$C[d  
El}~3|a?  
]_ LAy  
//启动子线程 kb-XEJ}L  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;180ct4  
for(int i=0;i<nStartPos.length;i++) 1xxTI{'g[  
{ BDN}`F[F  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JA >&$h  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *h?*RUQ  
nStartPos,nEndPos,i); BDp(&=ktq  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); axG%@5  
fileSplitterFetch.start(); NrcV%-+u%  
} B <Jxj  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RCkmxO;b&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); __z/X"H  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }2=~7&)  
nEndPos = " + nFileLength); c7rC!v  
// fileSplitterFetch[nPos.length-1].start(); +o.#']}Pl  
&~"N/o  
Kj"n Id)  
//等待子线程结束 p@$92> '  
//int count = 0; o/U}G,|G  
//是否结束while循环 mv<cyWp  
boolean breakWhile = false; ?zo7.R-Vac  
}m!T~XR</  
p E1uD4lLb  
while(!bStop) (>Sy,  
{ 1\jj3Y'i'  
write_nPos(); JpQV7}$  
Utility.sleep(500); JWt@vf~  
breakWhile = true; #,j m3M qj  
3&X5*-U  
%*L8W*V  
for(int i=0;i<nStartPos.length;i++) ,[n=PJVw/  
{ zPvTRW~H\  
if(!fileSplitterFetch.bDownOver) zll?/|%  
{ kaZcYuT.9  
breakWhile = false; b^Do[o}5  
break; Dmtsu2o  
} %)}_OXWf:  
} 9dg+@FS}=  
if(breakWhile) `=TJw,q  
break; p=Q o92 NH  
FN0<iL  
*XXa 9z  
//count++; (Q"s;g  
//if(count>4) .>5E 4^$%  
// siteStop(); 7n#Mh-vq  
} i piS=  
]{-ib:f~  
Si;eBPFH  
System.err.println("文件下载结束!"); kKQD$g.z6  
} `C:J{`  
catch(Exception e){e.printStackTrace ();} )q7!CG'oY  
} ZYl*-i&~?  
QswFISch  
!&8B8jHqA  
//获得文件长度 !;PKx]/&  
public long getFileSize() 0@!-+}i  
{ =rNI&K_<  
int nFileLength = -1; &'5 j!  
try{ Yu9(qRK  
URL url = new URL(siteInfoBean.getSSiteURL()); e58tf3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $+ \JT/eG9  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;;17 #T2  
ds+0y;vc  
=sXk,I;  
int responseCode=httpConnection.getResponseCode(); ]gb?3a}A  
if(responseCode>=400) uQkFFWS  
{ [MM`#!K%  
processErrorCode(responseCode); uY )|   
return -2; //-2 represent access is error j&?@:Zg v  
} 0bIhP,4&  
q-0( Wx9|  
CwzDkr&QC_  
String sHeader; |A u+^#:;  
$T'lWD*  
/vPcg  
for(int i=1;;i++) al Q:'K  
{ ;x=0+0JD  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7OZjLD{ID  
//Utility.log(in.readLine()); \H?r[]*c%  
sHeader=httpConnection.getHeaderFieldKey(i); a/ Z\h{*  
if(sHeader!=null) {Ve_u  
{ rcMSso2  
if(sHeader.equals("Content-Length")) f,Dj@?3+  
{ _$qH\>se  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LT '2446  
break; &FzZpH  
} #.W<[KZf  
} ytGcigw(P  
else ,dk!hm u  
break; xCiq;FFR  
} [lAZ)6E~=  
} pj'[ H  
catch(IOException e){e.printStackTrace ();} v+`gQXJ"G  
catch(Exception e){e.printStackTrace ();} =I9RM9O<  
7pz #%Hf  
sZPA(N?  
Utility.log(nFileLength); FAd4p9[Y  
}7|UA%xz  
$> PV6  
return nFileLength; h.h\)>DM@  
} | Xk>a7X  
odpjEeQC  
|`6*~ciUV  
//保存下载信息(文件指针位置) H(j983  
private void write_nPos() b\Gw|?Rv  
{ DlbNW& V  
try{ KdtQJ:_`k  
output = new DataOutputStream(new FileOutputStream(tmpFile)); T|Fl$is  
output.writeInt(nStartPos.length); lK3Z}e*eXQ  
for(int i=0;i<nStartPos.length;i++) (E?X@d iu  
{ m&8'O\$  
// output.writeLong(nPos); ^NiS7)FX  
output.writeLong(fileSplitterFetch.nStartPos); %FO# j6  
output.writeLong(fileSplitterFetch.nEndPos); Tf?|*P  
} 3It9|Y"6[  
output.close(); &,~Oi(SX5  
} aRF}F E,u  
catch(IOException e){e.printStackTrace ();} ]eZrb%B .  
catch(Exception e){e.printStackTrace ();} R<x~KJ11c  
} :HQQ8uQfb  
x.~AvJ  
}0~4Z)?e3  
//读取保存的下载信息(文件指针位置) 1|Z!8:&pj  
private void read_nPos() .:=G=v=1  
{ -mK;f$X  
try{ EG[Rda  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i"o %Gc  
int nCount = input.readInt(); &ywU^hBh  
nStartPos = new long[nCount]; K.K=\ Y2  
nEndPos = new long[nCount]; uMe]].04  
for(int i=0;i<nStartPos.length;i++) DNl '}K1W  
{ o& "nF+,  
nStartPos = input.readLong(); e2l!L*[g  
nEndPos = input.readLong(); xRM)f93@  
} 1x~dsM;q  
input.close(); %gE*x #  
} 1MnT*w   
catch(IOException e){e.printStackTrace ();} jou741  
catch(Exception e){e.printStackTrace ();} a"&Gs/QKSC  
} m3E`kW |  
j>-O'CO  
7[?{wbq  
private void processErrorCode(int nErrorCode) "nEfk{g  
{ q t!0#z8  
System.err.println("Error Code : " + nErrorCode); Ryrvu1 k  
} P4S]bPIp  
YZ0Jei8+-  
@is!VzE  
//停止文件下载 [=q&5'FY0  
public void siteStop() ^J-\s_)"  
{ Tweku}D7  
bStop = true; (TJ )Y7E  
for(int i=0;i<nStartPos.length;i++) dGY:?mf&  
fileSplitterFetch.splitterStop(); !O }^Y  
^TF71u o  
/I/gbmc)  
} I c 2R\}q  
} Z0I>PBL@l  
//负责部分文件的抓取 ;Wu6f"+Y#  
**FileSplitterFetch.java 8\ { 1y:|  
*/ _gl7Ma  
package NetFox; ^\ocH|D  
~ '/Yp8 (  
1Vy8TV3D  
import java.io.*; \DC0`  
import java.net.*; tlJ@@v&=  
-- chU5  
+1o4l i  
public class FileSplitterFetch extends Thread { KrDG  
# %$U-ti  
A, ;V|jv9  
String sURL; //File URL M4`. [P4  
long nStartPos; //File Snippet Start Position /l&$B  
long nEndPos; //File Snippet End Position nA?Ks!9T  
int nThreadID; //Thread's ID EYD24  
boolean bDownOver = false; //Downing is over z[~ph/^  
boolean bStop = false; //Stop identical gJC~$/2  
FileAccessI fileAccessI = null; //File Access interface vlS+UFH0  
3BzC'nplm  
9`X}G`  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b>Em~NMu_  
{ :[C"}m R1  
this.sURL = sURL; L.tW]43K  
this.nStartPos = nStart; rZSD)I  
this.nEndPos = nEnd; 0c6Ea>S[  
nThreadID = id; GI _.[  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }s++^uX6  
} 6I!B>V#U+  
g/f^|:  
O-jpS?@  
public void run() 3JJEj1O  
{ t#BQB<GI  
while(nStartPos < nEndPos && !bStop) UHT2a9rG  
{ o;5ns  
]u<8j r  
)~[rb<:)b  
try{ V|W[>/  
URL url = new URL(sURL); cWS 0B $$  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `+0K~k|DC  
httpConnection.setRequestProperty("User-Agent","NetFox"); la}Xo0nq0+  
String sProperty = "bytes="+nStartPos+"-"; BDiN*.w5  
httpConnection.setRequestProperty("RANGE",sProperty); DO{Lj# @  
Utility.log(sProperty); >Xv Fg  
>#Ue`)d`aY  
u]uZc~T  
InputStream input = httpConnection.getInputStream(); RR9G$}WS(  
//logResponseHead(httpConnection); ;\48Q;  
xjK@Q1MJ  
+ko-oZ7V  
byte[] b = new byte[1024]; e WWtMnq  
int nRead; )N'rYS' 9  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) sRK oM  
{ k|D =Q  
nStartPos += fileAccessI.write(b,0,nRead); ,|G~PC8  
//if(nThreadID == 1) I:Q3r"1  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cfhiZ~."T  
} _k O<|ev  
\;bDDTM  
J-d>#'Wb|  
Utility.log("Thread " + nThreadID + " is over!"); *1c1XN<7  
bDownOver = true; e61e|hoX\  
//nPos = fileAccessI.write (b,0,nRead); q)rxv7Iu\  
} ]7DS>%m Y(  
catch(Exception e){e.printStackTrace ();} Yx"un4  
} K zWqHq  
} gO%o A} !i  
p|9Eue3j2  
bTepTWv  
//打印回应的头信息 .6HHUy  
public void logResponseHead(HttpURLConnection con) $3)Z>p   
{ e.VR9O]G  
for(int i=1;;i++) q:ah%x[  
{ s)9d\{  
String header=con.getHeaderFieldKey(i); O~DdMW  
if(header!=null) 6O\a\z  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sX[k}=HCK  
Utility.log(header+" : "+con.getHeaderField(header)); -a\[`JHi  
else !}I+)@~\w  
break; -?vII~a9y  
} ]Mb:zs<r  
} !&#5 *  
V<ExR@|}.%  
Gk-49|qIV  
public void splitterStop() y)uxj-G  
{ hA:RVeS{  
bStop = true; O0RV>Ml'&  
} .{,fb  
M T]2n{e  
4D=^24f`0  
} Aw"Y_S8.  
`RHhc{  
C7Ny-rj}IA  
/* Gph:'3 *X  
**FileAccess.java ?M9?GodbP.  
*//文件访问(定位,写) JrNqS[c/  
package NetFox; pKNrEq  
import java.io.*; @5tGI U;1  
BRTCo,i  
KybrSa  
public class FileAccessI implements Serializable{ \$W\[s4I  
qW 2'?B3<  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /7LAd_P6  
RandomAccessFile oSavedFile; e]zd6{g[m  
long nPos; ~ya@ YP]';  
EK2mJCC|  
Aq;WQyZ2  
public FileAccessI() throws IOException 'y%*W:O  
{ sg%Ptp  
this("",0); N:~CN1  
} SL 5QhP  
fjh,e  
we&D"V  
public FileAccessI(String sName,long nPos) throws IOException cH6<'W{*  
{ a?1Ml>R6P  
oSavedFile = new RandomAccessFile(sName,"rw"); 'bn$"A"{o  
this.nPos = nPos; p-f"4vH  
oSavedFile.seek(nPos); 'n/L1Fn  
} D]'/5]~z<  
rcUJOI  
$A^OP{  
public synchronized int write(byte[] b,int nStart,int nLen) %4^NX@1jV  
{ |3P dlIbO  
int n = -1; 0P l>k'9  
try{ 7p_B?r  
oSavedFile.write(b,nStart,nLen); ;!pSYcT,  
n = nLen; 4_W*LG~2s  
} )MeeF-Ad6  
catch(IOException e) O#n=mJ  
{ dM)x|b3z  
e.printStackTrace (); Ef\&3TcQ  
} L]wk Ba  
\\Te\l|L  
YckLz01jh  
return n; )R6-]TkA_  
} $0&<Jx  
s_ %LU:WC  
a_(T9pr  
} iyTKy+3A  
yn|U<Hxl~H  
@M!nAQ8hY  
/* @&f~#Xe  
**SiteInfoBean.java E-v^eMWX  
*/ Jxsch\  
package NetFox; |Ng}ZLBM  
RC~C}  
E~ +g6YlT  
public class SiteInfoBean { ub9,Wd"^  
EI8KKo *  
:=?od 0]W  
private String sSiteURL; //Site's URL 9s&dN  
private String sFilePath; //Saved File's Path MeDlsO  
private String sFileName; //Saved File's Name CPci 'SO  
private int nSplitter; //Count of Splited Downloading File Mn TqWC90  
!0X/^Xv@=  
#b>D^=NV>)  
public SiteInfoBean() tvcM< e20  
{//nSplitter的缺省值为5 D]?yGI_  
//default value of nSplitter is 5 F*p@hl  
this("","","",5); mWTV)z57  
} dmPAPCm%y  
1otE:bi  
UId?a} J  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter)  ?)2;W  
{ f0"_ {\  
sSiteURL= sURL; K;*B$2Z#k  
sFilePath = sPath; [7Liken  
sFileName = sName; KJi8LM  
this.nSplitter = nSpiltter; .f9&.H#  
j5!pS xOC  
`%_(_%K  
} h~5gHx/ a  
r1[#_A`Yn  
Odr<fvV,>  
public String getSSiteURL() 8+Abw)]s  
{ 46D _K  
return sSiteURL; =)f5JwZPG  
} 6r)B|~,OA  
yX%NFXD  
Oid;s!-S6  
public void setSSiteURL(String value) O #5`mo  
{ r#NR3_@9  
sSiteURL = value; ~(}n d  
} +Uxt xl'  
an)Z.x  
F7\nG}#s  
public String getSFilePath() }BAe   
{ C 4K"eX,K  
return sFilePath; V-ONC  
} ;^ff35EE8  
$GQ{Ai:VwF  
/ >O.U?  
public void setSFilePath(String value) iQvqifDmh  
{ M3s:B& /  
sFilePath = value; "c*#ZP  
} 0}9  
#Yx /ubg6  
"ZP)[ [Rd  
public String getSFileName() R'$1,ie  
{ |?\2F   
return sFileName; XGAR8=tic  
} uQ3W =  
Ygc.0VKMR  
8Ud.}< Zi  
public void setSFileName(String value) Q1RUmIe_&  
{ KouIzWf.  
sFileName = value; H]( TSt<Q"  
} 2#@-t{\3-p  
3j\Py'};  
!RwMUnp  
public int getNSplitter() Dv}VmC""  
{ i2?TMM!Fe  
return nSplitter; $d Nmq  
} }b+$S'`Bv  
3w8v.J8q  
K_-S`-eH  
public void setNSplitter(int nCount) dG)}H _  
{ &{S@v9~IT  
nSplitter = nCount; b q8nV  
} ,"Nb;Yhg  
} wLKC6@ W  
QJ,~K&?  
U]"6KS   
/* t:%u4\nZ;  
**Utility.java q U^`fIa  
*/ ' pfkbmJ  
package NetFox; },,K6*P  
@Uqcym.  
NW~`oc)NS  
public class Utility { UVD*GsBk  
yH(%*-S  
e/zz.cd){  
public Utility() $u, ~183  
{ < ;fI*km  
+@MG$*}Oz  
Yq%r\[%*  
} Ur(<  ]  
%8lWJwb7u  
//线程睡眠 |z`AIScT  
public static void sleep(int nSecond) QxiAC>%K  
{ t]+h.  
try{ vlPViHF.  
Thread.sleep(nSecond); UxvT|~"  
} =W"9a\m  
catch(Exception e) cD9.L  
{ qjH/E6GGg  
e.printStackTrace (); HJ!P]X_J1  
} WnQ+  
} ?-=<7 ~$  
w%~Mg3|  
//日志 G3gEL)b*  
public static void log(String sMsg) d+]/0J!c  
{ n8o(>?Kw  
System.err.println(sMsg); e84O 6K6o  
} y)T|1)  
G`z=qaj  
' [%?j?2r  
public static void log(int sMsg) ( c +M"s  
{ Iy@6cd,)S  
System.err.println(sMsg); )@6iQ  
} w5q'M  
} PDpDkcy|QM  
_.5AB E  
 dQI6.$?  
/* ^@;P-0Sy  
**TestMethod.java R?8/qGSVqJ  
*/ nQd~i0`vB  
package NetFox; 3e1^r_YI  
T *rz#O  
S{UEV7d:n0  
public class TestMethod { M+WN\.2pX  
gNSsT])  
 #{zF~/Qq  
public TestMethod() +[Q`I*C  
{ ///xx/weblogic60b2_win.exe uOb}R   
try{ Z + )<FX  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -Hg,:re2  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V(F1i%9lg  
SiteFileFetch fileFetch = new SiteFileFetch(bean); YRU#/TP  
fileFetch.start(); _s+_M+@et  
} cfL:#IM  
catch(Exception e){e.printStackTrace ();} b#Vm;6BHD1  
) -@Dh6F  
#g]eDU-[  
} hv)d  
mf\@vI  
] jycg@=B  
public static void main(String[] args) vzZ"TSP  
{ 6IKi*}  
new TestMethod(); =6[R,{|C  
} ]GXE2A_i;  
} PGA `R  
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