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http断点续传简单实现(java)

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/* Eu.qA9,@U  
**SiteFileFetch.java U^BXCu1km  
*/ MmH_gR  
package NetFox; KxmPL  
import java.io.*; fMPq  
import java.net.*; Q0Qm0B5eY  
k<zGrq=8J  
Ks2%F&\cE  
public class SiteFileFetch extends Thread { %C0O?q  
pm@Z[g  
IA#*T`  
SiteInfoBean siteInfoBean = null; //文件信息Bean e uHu}  
long[] nStartPos; //开始位置 O>M*mTM  
long[] nEndPos; //结束位置 #UCQiQfP  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 yVQz<tX|  
long nFileLength; //文件长度 KGmc*Jwy  
boolean bFirst = true; //是否第一次取文件 wn|@D<  
boolean bStop = false; //停止标志 ^@L l(?  
File tmpFile; //文件下载的临时信息 I7z/GA\x  
DataOutputStream output; //输出到文件的输出流 J?quYlS  
cN}A rv  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) jI`To%^ Y  
public SiteFileFetch(SiteInfoBean bean) throws IOException Kx 185Q'W  
{ np\2sa`  
siteInfoBean = bean; *M<BPxh0w]  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Dh(T) yc  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); !riMIl1  
if(tmpFile.exists ()) f\_!N "HW  
{ [j]J_S9jJ  
bFirst = false; ec4%Wk2  
read_nPos(); ]!G>8Rc  
} <`j[;>O  
else 2vdQ&H4  
{ *a,.E6C*  
nStartPos = new long[bean.getNSplitter()]; |4> r"  
nEndPos = new long[bean.getNSplitter()]; =#2qX> ?  
} ^}/ E~Sg7\  
W$Q)aA7  
*r,&@UB  
:8Ts'OGwI  
} eO PCYyN  
k.xv+^b9Q  
`}8@[iB'  
public void run() Q=L$7   
{ maUHjI 5A-  
//获得文件长度 }42qMOi#w1  
//分割文件  vs])%l%t  
//实例FileSplitterFetch <Z:8~:@  
//启动FileSplitterFetch线程 pebx#}]p-  
//等待子线程返回 -C-OG}XjI  
try{ @W\4UX3dK  
if(bFirst) ddq 1NW  
{ pY!dG-;  
nFileLength = getFileSize(); +>:_kE]?nX  
if(nFileLength == -1) /z)3gsF  
{ @S"pJeP/f  
System.err.println("File Length is not known!"); a3dzok  
} Hl2f`GZ   
else if(nFileLength == -2) U]!.~ji3  
{ +.(}u ,:8  
System.err.println("File is not access!"); YUVc9PV)Ws  
} 7hF,gl5  
else OT}Yr9h4  
{ O`[iz/7m  
for(int i=0;i<nStartPos.length;i++) yEpN,A  
{ $mI:Im`s  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ZA_zKJ[[7  
} nze1]3`  
for(int i=0;i<nEndPos.length-1;i++) Ih-3t*L  
{ =SK+ \j$  
nEndPos = nStartPos[i+1]; w{e3U7;  
} jQxPOl$-  
nEndPos[nEndPos.length-1] = nFileLength; ,hTwNVWI9  
} '6.>Wdd  
} 0qL V(L  
mzV"G>,o  
/,Dwu?Lcqp  
//启动子线程 ]o[X+;Tj|  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b1+hr(kMRM  
for(int i=0;i<nStartPos.length;i++) 9oj e`Ay  
{ #7~tL23}]  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uH ny ]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !M]%8NTt2  
nStartPos,nEndPos,i); :,%J6Zh?  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?zhI=1 ED%  
fileSplitterFetch.start(); 3Zaq#uA  
} *qO]v9 j  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9QOr,~~s  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dE5 5  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lRv#1'Y  
nEndPos = " + nFileLength); u 5Eo  
// fileSplitterFetch[nPos.length-1].start(); k_K,J 6_)  
$#G6m`V  
/zl3&~4  
//等待子线程结束 4/HY[FT  
//int count = 0; |.Nr.4Yp  
//是否结束while循环 sP6 ):h  
boolean breakWhile = false; 6^] `-4*W  
;# R3k  
?#BZ `H  
while(!bStop) JNxW6 cK  
{ #aitESbT  
write_nPos(); q,;".3VQ  
Utility.sleep(500); BcZEa^^~os  
breakWhile = true; ERfd7V<c>  
]r/(n]=(  
d7W%zg\T  
for(int i=0;i<nStartPos.length;i++) ;OQ'B=uK  
{ 670J{b  
if(!fileSplitterFetch.bDownOver) #$rf-E5g-K  
{ 7y>Tn`V8G  
breakWhile = false; I%;Rn:zl  
break; < -Hs<T|tW  
} !y>lOw})Q  
} DC$7B`#D  
if(breakWhile) %PQldPL8  
break;  &7L~PZ  
HCX!P4Hj  
84[|qB,ML  
//count++; d3EjI6R*z  
//if(count>4) Wk/fB0  
// siteStop(); 4r_!>['`"  
} W:VW_3  
P<>[e9|  
?@Z7O.u  
System.err.println("文件下载结束!"); ?gd'M_-J,  
} <WM -@J(1  
catch(Exception e){e.printStackTrace ();} `xISkW4%  
} "NxOOLL  
5c<b|  
b%3Q$wIJ6  
//获得文件长度 Xy[}Gp  
public long getFileSize() nHI(V-E2:H  
{ gb]h OB7g  
int nFileLength = -1; D",A$(lG  
try{ :0nK`$'  
URL url = new URL(siteInfoBean.getSSiteURL()); Ezi' 2Sc  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VKT@2HjNT`  
httpConnection.setRequestProperty("User-Agent","NetFox"); |2qR^Hd&5  
w>v5oy8s-  
sk#9x`Rw  
int responseCode=httpConnection.getResponseCode(); h^['rmd  
if(responseCode>=400) $TR=3[j  
{ n)tU9@4Np  
processErrorCode(responseCode); K1;z Mh  
return -2; //-2 represent access is error dj3|f{kg{  
} UV?[d:\>'  
M,&tA1CH  
d0'7efC+  
String sHeader; ~af8p {  
qO7fbql_  
$RpF xi  
for(int i=1;;i++) (2: N;  
{ +:}kZDl@ X  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ());  NI^{$QMj  
//Utility.log(in.readLine()); b([:,T7  
sHeader=httpConnection.getHeaderFieldKey(i); y^9bfMA  
if(sHeader!=null) I9;xzES  
{ S<V-ZV&_:U  
if(sHeader.equals("Content-Length")) TKK,Y{{  
{ 1d`cTaQ-  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K-Re"zsz  
break; 8098y,mQe  
} bi+9R-=&  
} KCE=|*6::|  
else 5n:nZ_D  
break; g&Z"_7L~  
} N A8 sN  
} _jW>dU^B  
catch(IOException e){e.printStackTrace ();} 9p5= _  
catch(Exception e){e.printStackTrace ();} %z30=?VL  
P%iP:16  
:*=Ns[Y  
Utility.log(nFileLength); iM8sX B  
\e_IFISC  
{JXf*IJ  
return nFileLength; kl=xu3j  
} D2{L=  
2v4W6R  
SBC~QD>L+  
//保存下载信息(文件指针位置) ?fB5t;~E  
private void write_nPos() K6-6{vt  
{ FzVZs# O  
try{ lBS"3s384  
output = new DataOutputStream(new FileOutputStream(tmpFile)); \]t]#D>0  
output.writeInt(nStartPos.length); 5~QhX22  
for(int i=0;i<nStartPos.length;i++) tbg*_ZQO u  
{ 3eWJt\}?B  
// output.writeLong(nPos); 2H6:np |O  
output.writeLong(fileSplitterFetch.nStartPos); ?gU}[]  
output.writeLong(fileSplitterFetch.nEndPos); ka/nQ~_#<  
} b(/j\NWC  
output.close(); XJc ,uj7  
} -ovoRI^6`}  
catch(IOException e){e.printStackTrace ();} l(#1mY5!q8  
catch(Exception e){e.printStackTrace ();} [O(m/  
} 0',[J  
M%3Wy"YQ,n  
(nq^\ZdF  
//读取保存的下载信息(文件指针位置) _p0)vT  
private void read_nPos() @$oZ|ZkZ  
{ 0iF-}o  
try{ @' d6iYk_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "sD1T3!\)Q  
int nCount = input.readInt(); w=|py>%  
nStartPos = new long[nCount]; wE?CvL  
nEndPos = new long[nCount]; JwB"\&'1ZS  
for(int i=0;i<nStartPos.length;i++) cu)U7  
{ @cPflb  
nStartPos = input.readLong(); Vu%n&uF  
nEndPos = input.readLong(); Y KY2Cw  
} yWNOG 2qAP  
input.close(); &f"T,4Oh  
} 7|Xe&o<n  
catch(IOException e){e.printStackTrace ();} g>_OuQ|c  
catch(Exception e){e.printStackTrace ();} b;*c:{W)  
} _H8*ReFG  
Zb"jB$58  
PYu$1o9+N  
private void processErrorCode(int nErrorCode) a_MFQf&KV  
{ Ia#"/`||  
System.err.println("Error Code : " + nErrorCode); <*_o0;h|  
} d+0^u(gc!8  
[3kl^TE  
+mLD/gK`  
//停止文件下载 Dm^l?Z  
public void siteStop() #~S>K3(  
{ Q,~x#  
bStop = true; >nK%^T  
for(int i=0;i<nStartPos.length;i++) F_v-}bbcFQ  
fileSplitterFetch.splitterStop(); |kseKZ3  
*,&S',S-  
0yaMe@&,  
} 57<Di!rt  
} x}|+sS,g  
//负责部分文件的抓取 \sITwPA[z  
**FileSplitterFetch.java dZDK7UL  
*/ 85D? dgV  
package NetFox; ^&MK42,\  
SB/3jH  
}vY.EEy!  
import java.io.*; t!:)L+$3  
import java.net.*; o0l7 4  
<aXoB*Y  
\E77SO,$  
public class FileSplitterFetch extends Thread { 5B?i(2&#  
Im+ 7<3Z  
!b63ik15O~  
String sURL; //File URL WL1\y|  
long nStartPos; //File Snippet Start Position $ser+Jt=  
long nEndPos; //File Snippet End Position ceG&,a$\  
int nThreadID; //Thread's ID A? r^V2+j  
boolean bDownOver = false; //Downing is over 'g hys1H  
boolean bStop = false; //Stop identical VX!hv`E  
FileAccessI fileAccessI = null; //File Access interface SO_>c+Dw  
s4bv;W  
5z Kqb  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]Jn2Ra"j  
{ JD*8@N  
this.sURL = sURL; 03_pwB)^  
this.nStartPos = nStart; mf9hFy* <4  
this.nEndPos = nEnd; Mg\TH./Y:  
nThreadID = id; *VDVC0R  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 iZ "y7s  
} lE'wfUb  
)~dOmfw%|  
PS}73Y#  
public void run() M)O [j}N  
{ 6.19g'{sB  
while(nStartPos < nEndPos && !bStop) 1qZG`Vz  
{ ^1 ;BiQ  
e2wvc/gG6  
^V .'^=l  
try{ h/?6=D{  
URL url = new URL(sURL); SY T$3|a  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;MPKJS68@  
httpConnection.setRequestProperty("User-Agent","NetFox"); 9go))&`PJL  
String sProperty = "bytes="+nStartPos+"-"; T?rH ,$:  
httpConnection.setRequestProperty("RANGE",sProperty); > c:Zx!  
Utility.log(sProperty); #c:kCZt#  
E-SG8U;  
8wmQ4){  
InputStream input = httpConnection.getInputStream(); )4m_A p\  
//logResponseHead(httpConnection); d.AC%&W  
 :,~K]G  
E}YI WTX  
byte[] b = new byte[1024]; 9!#EwPD$#  
int nRead; n[CoS  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M*`hDdS  
{ y/tSGkMv  
nStartPos += fileAccessI.write(b,0,nRead); $r15gfne>  
//if(nThreadID == 1) F0.zi>5  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &d,Wy"WPi  
} ]0-<>  
vaB!R 0  
Y0RgJn  
Utility.log("Thread " + nThreadID + " is over!"); ^Xs]C|=W  
bDownOver = true; q.T:0|  
//nPos = fileAccessI.write (b,0,nRead); H,K`6HH  
} ?1w"IjUS  
catch(Exception e){e.printStackTrace ();} a g;dc  
} FN\GE\H  
} kOI !~Qk  
(a#pvEY  
o;J;k_[MX  
//打印回应的头信息 6t m \L  
public void logResponseHead(HttpURLConnection con) O{ q&]~,  
{ vRr9%zx  
for(int i=1;;i++) V3uXan_  
{ &<0ZUI |S3  
String header=con.getHeaderFieldKey(i); Z@M6!;y#  
if(header!=null) \fi}Q\|C  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Nfb`YU=  
Utility.log(header+" : "+con.getHeaderField(header)); X-/Ban  
else bVK$.*,  
break;  }_%P6  
} {y-`QS  
} "DpKrVuG  
I$j|Rq  
J-XTN"O  
public void splitterStop()  zy>}L #  
{ .8H}Lf\  
bStop = true; (0C&z/  
} AC4 l<:Yh  
x~+-VF3/  
mi^hvks<  
} S^j,f'2  
(U9a@ 1  
s|2}2<+  
/* PGX+p+wB  
**FileAccess.java CDCC1BG"  
*//文件访问(定位,写) ti9}*8  
package NetFox; W[|[;{  
import java.io.*; c;!9\1sr  
3.),bm  
WQKj]:qk0  
public class FileAccessI implements Serializable{ OKPJuV`y6  
_tWE8 r,  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }N,>A-P  
RandomAccessFile oSavedFile; ],&\%jd<  
long nPos; ])N%^Qe$U  
% wL,v.}  
.@k*p>K  
public FileAccessI() throws IOException KyLp?!|>  
{ MZ~.(&  
this("",0); M[s\E4l:t  
} d+5:Qrr  
zH=hI Vc  
Dl A Z"C  
public FileAccessI(String sName,long nPos) throws IOException #ZTLrq5b  
{ _]o5R7[MQ  
oSavedFile = new RandomAccessFile(sName,"rw"); t.U{Bu P  
this.nPos = nPos; Pz`hX$  
oSavedFile.seek(nPos); \]8i}E1  
} hk;bk?:m  
*h:kmT  
zYr z08PJ  
public synchronized int write(byte[] b,int nStart,int nLen) D9o*8h2$  
{ qjLo&2)  
int n = -1; aQ|hi F}  
try{ 8*Zvr&B,G  
oSavedFile.write(b,nStart,nLen); 4bI*jEc\[  
n = nLen; ~6d5zI4\  
} 3cThu43c  
catch(IOException e) [Vp\$;\nT  
{ Le&;g4%  
e.printStackTrace (); :e2X/tl#  
} v}P!HczmMP  
N-QCfDao  
`~nCbUUee  
return n; =]b9X7}  
} gZ`DT  
`bqzg  
|Fp'/~|w2d  
} wd+O5Lr.R  
.bfST.OA  
 ?Ib}  
/* b:Dg}  
**SiteInfoBean.java / O)6iJ  
*/ >{XScxaB`  
package NetFox; $1e pf  
uV77E*+7\  
yjpz_<7a=  
public class SiteInfoBean { f_'"KF[%  
-tyaE  
} 07r  
private String sSiteURL; //Site's URL ? s4oDi|:  
private String sFilePath; //Saved File's Path 1b[NgOXY=  
private String sFileName; //Saved File's Name c F=P!2 @  
private int nSplitter; //Count of Splited Downloading File SQ<f  
KN, 4@4  
3EOyq^I%  
public SiteInfoBean() }]GbUC!Zb  
{//nSplitter的缺省值为5 J6auUm` `  
//default value of nSplitter is 5 4J}3,+  
this("","","",5); !. eAOuq  
} "TFwHe3C4  
26PD[af64O  
x4 hO$3o  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `]{Psc6_=  
{ ,`)OEI|1d  
sSiteURL= sURL; ccMd/  
sFilePath = sPath; :rmauKR  
sFileName = sName; AT ymKJ  
this.nSplitter = nSpiltter; iNLDl~uU  
pVz*ZQ[]  
GNZ#q)qT  
} {(0Id!  
fTgbF{?xh  
}4KW@L[g  
public String getSSiteURL() '!@A}&]  
{ 8Fx]koP.  
return sSiteURL; mu>] 9ZW  
} /.@x 4cdS  
. s-5N\  
xB,/dMdTj  
public void setSSiteURL(String value) +7Rt{C,  
{ iAHZ0Du  
sSiteURL = value; 2@ *<9-9  
} 5Pqt_ZWy  
O! (85rp/  
H &fTh  
public String getSFilePath() nl9kYE [  
{ [yF^IlSs  
return sFilePath; :`5;nl63  
} |0]YA  
)f[C[Rd  
%mL5+d-oP  
public void setSFilePath(String value) ;-Ado8  
{ `u=oeM :  
sFilePath = value; 5"uNj<.V  
} y($EK(cb  
OPLl*bnf  
f}blB?e  
public String getSFileName() wt\m+!u`  
{ y9ip[Xn-$:  
return sFileName; =h7[E./U1  
} |?yE^$a  
xD^wTtT  
pJ6Jx(  
public void setSFileName(String value) Rdj8 *f  
{ ?sE@]]z  
sFileName = value; {83C,C-  
} J@gm@ jLc  
"u5KbJW  
PY\W  
public int getNSplitter() jJ<;2e~OW  
{ (gD Q\t@3-  
return nSplitter; ;t~*F#p(!  
} lJlhl7  
$':JI#  
sX!3_ '-  
public void setNSplitter(int nCount) G ~A$jStm  
{ }pK v.  
nSplitter = nCount; Q!`)e@r  
} XJ O[[G`  
} zF?31\GOX  
$8Ig&k|~8  
 d~sJ=)  
/* M6&~LI.We=  
**Utility.java #)FDl70S8  
*/ 73VQ@J n  
package NetFox; #1B}-PGCm  
Enu!u~1]F  
F$[)Bd/"  
public class Utility { m|lM.]2_  
]  ~'9  
aU4R+.M7@  
public Utility() brj[c>ID  
{ aj?2jU~Pq  
*|^,DGfQ6  
;}UzJe ,S  
} L,WkJe3  
'V1!&Q6  
//线程睡眠 %pH)paRAP  
public static void sleep(int nSecond) lS#7x h  
{ X:U=MWc>  
try{ tg3zXJ4k_  
Thread.sleep(nSecond); H<$pHyxU  
} x\6] ;SXX  
catch(Exception e) o>.AdZby  
{ 2G ZF/9}  
e.printStackTrace (); p%tE v  
} Jb7iBQ2%  
} `t%|.=R  
D/e&7^iK  
//日志 iQu^|,tHEM  
public static void log(String sMsg) |^ ?`Q.|c$  
{ <>VID E  
System.err.println(sMsg); Qg[heND  
} b$dBV}0 L  
 8>ESD}(  
>B`Cch/ 'U  
public static void log(int sMsg) t?KUK>>w  
{ ::v;)VdX+*  
System.err.println(sMsg); - Sx0qi'%  
} aXX,Zu^  
} 4{Q$!O>  
1k$2LQ  
eU`;L [  
/* ]F !'M  
**TestMethod.java 3xP~~j;7  
*/ JR] )xPI`  
package NetFox; Kq$:\B)<c  
@51z-T  
l +|1G  
public class TestMethod { cW=Qh-`jU;  
U[IQ1AEr  
0,:iE\  
public TestMethod() $|rCrak;  
{ ///xx/weblogic60b2_win.exe +I*k0"gj6  
try{ h] <GTWj  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _cR6ik zW(  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NS h%t+XU]  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3T"2S[gT  
fileFetch.start(); VIb;96$Or  
} I+*osk  
catch(Exception e){e.printStackTrace ();} B^H4Q 4-  
j'\>Nn+  
!&qx7eOSpP  
} &Q2NU$  
yVT&rQ"{  
pi|\0lH6W  
public static void main(String[] args) ]gb _Nv  
{ +8]W\<Kp  
new TestMethod(); }*0,>w>  
} f+{c1fb>s  
} ur?d6 a  
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