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http断点续传简单实现(java)

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/* n.,\Z(l|0  
**SiteFileFetch.java M)6_Ta l  
*/ -yOrNir}W  
package NetFox; .hlr)gF&)  
import java.io.*; ="3Hc=1?R  
import java.net.*; Z=DAA+T`  
2}1(j  
c]F$$BT  
public class SiteFileFetch extends Thread { di`Ql._M  
oddS~lW  
>+R`3|o '  
SiteInfoBean siteInfoBean = null; //文件信息Bean q~.\NKc  
long[] nStartPos; //开始位置 Q4-d2I>0  
long[] nEndPos; //结束位置 ,JRYG<O_T  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 -]\%a=]  
long nFileLength; //文件长度 L.lmbxn  
boolean bFirst = true; //是否第一次取文件 R3wK@D  
boolean bStop = false; //停止标志 ~m y\{q  
File tmpFile; //文件下载的临时信息 (L8H.|.  
DataOutputStream output; //输出到文件的输出流 0)-l9V  
+60zJ 4  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) { dwm>a  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5NbI Vz  
{ Fkj\U^G  
siteInfoBean = bean; 9*RfOdnNe  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); =(K;z9OR  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); m C_v!nL.  
if(tmpFile.exists ()) tTe\#o`  
{ &CF74AN#  
bFirst = false; EbuOPa  
read_nPos(); :gVz}/C.@  
} [3;J,P=&  
else m!a<\0^  
{ %FLz}QW*  
nStartPos = new long[bean.getNSplitter()]; W}+Q!T=  
nEndPos = new long[bean.getNSplitter()]; O[3J Px  
} &6FRw0GX  
a*6x^R;)  
+Vt@~Z4K  
bSU9sg\  
} 2X;,s`)  
/!oi`8D  
${ad[hs  
public void run() Sm;&2"  
{ 0FsGqFt  
//获得文件长度 AF ZHS\  
//分割文件 IfeG"ua|  
//实例FileSplitterFetch  .VuZ=  
//启动FileSplitterFetch线程 (A\qZtnyl  
//等待子线程返回 ]IXKoJUf  
try{ PDvqA{  
if(bFirst) 1wuLw Ad  
{ 1C^6'9o  
nFileLength = getFileSize(); D$;mur'  
if(nFileLength == -1) j\f;zb?F  
{ bw9a@X  
System.err.println("File Length is not known!"); _ mhP:O  
} }&d]Uv/4  
else if(nFileLength == -2) nBjfR2TuF  
{ ueZ`+g~gg  
System.err.println("File is not access!"); 5[]7baO)h1  
} k4'rDJfB  
else .Gh-T{\V'  
{ thOQcOf0$  
for(int i=0;i<nStartPos.length;i++) 0XSZ3dY&+  
{ ;n00kel$  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); EN` -- ^  
} QL"fC;xUn,  
for(int i=0;i<nEndPos.length-1;i++) 3X89mIDr  
{ &Ph@uZ\  
nEndPos = nStartPos[i+1]; B-|:l 7  
} YMj z , N  
nEndPos[nEndPos.length-1] = nFileLength; ;:vbOG#aSN  
} ^O6PZm5J}  
} $d{{><  
!h}x,=`z/  
{tk42}8k  
//启动子线程 3%|LMX]M5_  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]Hc `<P  
for(int i=0;i<nStartPos.length;i++) o?b$}Qrl  
{ P-ys$=  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -wvrc3F  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NwIl~FNK  
nStartPos,nEndPos,i); `]_#_  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VT?J TW  
fileSplitterFetch.start(); tmDI2Z%7  
} NjMbQ M4  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), } =?kf3k  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5Lo{\7%  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )/HSt%>  
nEndPos = " + nFileLength); &`0y<0z  
// fileSplitterFetch[nPos.length-1].start(); Z 3m5DK  
L10Vq}W"  
qi;@A-cq  
//等待子线程结束 Pan^@B=Q  
//int count = 0; he8y  
//是否结束while循环 Ms=x~o'  
boolean breakWhile = false; $L)9'X   
]$Ky ZHj{  
D\ HmY_  
while(!bStop) 320Wm)u>:  
{ DhG2!'N  
write_nPos(); 36@)a5  
Utility.sleep(500); `S2YBKz,1  
breakWhile = true; m%m/#\J E  
_=3H!b =  
|+mhYq|`  
for(int i=0;i<nStartPos.length;i++) vo-n9Bj  
{ '=G4R{  
if(!fileSplitterFetch.bDownOver) e57}.pF^  
{ IfF<8~~E  
breakWhile = false; 3:&!Q*i;  
break; yP :>vFd7  
} ~!E% GCyFy  
} fa8vY  
if(breakWhile) 4pJOJ!?  
break; U O YM   
lfOF]Kiqr  
_FeLSk.  
//count++;  4>uz'j<  
//if(count>4) wz+  
// siteStop(); R{NmWj['Mg  
} 'C]zB'H=  
[(B A:x1  
Nj1vB;4Nx  
System.err.println("文件下载结束!"); <8|vj 2d2  
} br .jj  
catch(Exception e){e.printStackTrace ();} _:x/\ 8P  
} f$Q#xlQM  
sycN  
u3R0_8 _.w  
//获得文件长度 9IIQon  
public long getFileSize() Vz1ro  
{ @2v L'6  
int nFileLength = -1; sOa`Tk  
try{ J Xo_l  
URL url = new URL(siteInfoBean.getSSiteURL()); $2A%y14  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rtS(iD@B"  
httpConnection.setRequestProperty("User-Agent","NetFox"); DM/J,q  
Qf6]qJa|  
L)H7~.Dj  
int responseCode=httpConnection.getResponseCode(); x|<rt96 6A  
if(responseCode>=400) /(8Usu?g.  
{ tQ< ou,   
processErrorCode(responseCode); T)6p,l  
return -2; //-2 represent access is error BEPeK  
} ,@tY D(Z  
\m1r(*Ar  
A7>0Pn%D3  
String sHeader; 3Ew-Ia%A  
*>n<7T0  
V.Dqbv  
for(int i=1;;i++) g05:A0X#  
{ ;JDn1(6  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \9geDX9A  
//Utility.log(in.readLine()); [?r`8K2!,  
sHeader=httpConnection.getHeaderFieldKey(i); ?;i O  
if(sHeader!=null) )TnxsFC  
{  0$b)@  
if(sHeader.equals("Content-Length")) qXR>Z=K<  
{ 5rRYv~+  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Tm-Nz7U^^  
break; h`-aO u  
} C|5eV=f)P  
} lsU|xOB  
else MLtfi{;LH  
break; |!euty ::  
} 6AKH0t|4  
} <%#M&9d)E  
catch(IOException e){e.printStackTrace ();} F-k3'eyY  
catch(Exception e){e.printStackTrace ();} P6&@fwJ<  
51W\%aB  
l3R`3@  
Utility.log(nFileLength); ;g?oU "YM  
dX-{75o5P  
{1li3K&0s  
return nFileLength; " |[w.`  
} F<Js"z+  
%Ui&SZ\  
'e_^s+l)a  
//保存下载信息(文件指针位置) L,*2t JcC<  
private void write_nPos() tPIT+1.]z  
{ xgn@1.}G  
try{ OE]z C  
output = new DataOutputStream(new FileOutputStream(tmpFile)); NVU@m+m~  
output.writeInt(nStartPos.length);  Iz*'  
for(int i=0;i<nStartPos.length;i++) f9W@!]LHJ  
{ jw?/@(AC6  
// output.writeLong(nPos); ;:,hdFap  
output.writeLong(fileSplitterFetch.nStartPos); k(+ EY%  
output.writeLong(fileSplitterFetch.nEndPos); Vcz ExP  
} w{f!t8C*s  
output.close(); v]& )+0  
} XrS.[  
catch(IOException e){e.printStackTrace ();} #56}RV1  
catch(Exception e){e.printStackTrace ();} /.9j$iK#  
}  ;)s$Et%  
wkOo8@J\  
E;.<'t>  
//读取保存的下载信息(文件指针位置) ~KHGh29  
private void read_nPos() ,#hS#?t   
{ OJPx V~y  
try{ }-?_c#G 3  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t}>6"^}U  
int nCount = input.readInt(); ~B;kFdcVXn  
nStartPos = new long[nCount]; 3[B*l@}j  
nEndPos = new long[nCount]; (Gr8JpV  
for(int i=0;i<nStartPos.length;i++) O]>9\!0{  
{ 4|YCBXWh  
nStartPos = input.readLong(); fw$/@31AP?  
nEndPos = input.readLong(); ;wwhW|A  
} 8!2NZOZOS  
input.close(); 8,=N~(pd`  
} Pz7{dQqjk#  
catch(IOException e){e.printStackTrace ();} pp@Jndlg  
catch(Exception e){e.printStackTrace ();} 4*'5EBa1  
} .lAqD-  
T4dLuJl  
k FE2Vv4.  
private void processErrorCode(int nErrorCode) Cj"+` C)l  
{ [[2Zcz:  
System.err.println("Error Code : " + nErrorCode); n[8ju,=  
} smvIU0:K  
Tj7OV}:  
teH.e!S  
//停止文件下载 )w(-Xc?P  
public void siteStop() 4Xt.}S!  
{ GEj/Z};;[b  
bStop = true; \ofWD{*j  
for(int i=0;i<nStartPos.length;i++) by!1L1[JTt  
fileSplitterFetch.splitterStop(); j oDY   
Sm(X/P=z  
)'3(=F$+l  
} 1)yEx1  
} 4XpW#>  
//负责部分文件的抓取 :tU&d(8  
**FileSplitterFetch.java -9TNU7^  
*/ aNLRUdc.  
package NetFox; H_RV#BW&  
l/0"'o_0v#  
11t+ a,fM  
import java.io.*; .RF ijr  
import java.net.*; DuX7  
{`?C5<r  
*'4+kj7>  
public class FileSplitterFetch extends Thread { 95LZG1]Rb  
=?g26>dYo  
r LQBaT7t#  
String sURL; //File URL CeQL8yJ;  
long nStartPos; //File Snippet Start Position {R<0 'JU  
long nEndPos; //File Snippet End Position q-gp;Fm  
int nThreadID; //Thread's ID H8.Aq\2S  
boolean bDownOver = false; //Downing is over ,l/~epx4v)  
boolean bStop = false; //Stop identical hG51jVYtw  
FileAccessI fileAccessI = null; //File Access interface L c4\i  
YHBH9E/B  
j_H"m R  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1AMxZ (e  
{ 9RA~#S|(T  
this.sURL = sURL; QJiU"1  
this.nStartPos = nStart; Y3@\uM`2#  
this.nEndPos = nEnd; \GhL{Awv&a  
nThreadID = id; 0'8_:|5  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y"zgpqJ  
} u~SvR~OE  
Hl-!rP.?0  
&Ui*w%  
public void run() IxN0m7  
{ 7|Z=#3INw  
while(nStartPos < nEndPos && !bStop) _+Tq&,_:o  
{ ^ [FK<9  
lh^-L+G:Ok  
kS_oj  
try{ Su.imM!  
URL url = new URL(sURL); r:pS[f|4\  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Mbbgsy3W  
httpConnection.setRequestProperty("User-Agent","NetFox"); `! ~~Wf'  
String sProperty = "bytes="+nStartPos+"-"; ;#-yyU  
httpConnection.setRequestProperty("RANGE",sProperty);  dxHKXw  
Utility.log(sProperty); %c+`8 wj  
12l-NWXf  
NqyKR&;  
InputStream input = httpConnection.getInputStream(); [R V_{F:'  
//logResponseHead(httpConnection); ,36AR|IO)  
T%0vifoQ_$  
o[Ojl .r<  
byte[] b = new byte[1024]; K @x4>9 3n  
int nRead; @o4+MQFn  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n-ZOe]3  
{ bu[PQsT  
nStartPos += fileAccessI.write(b,0,nRead); Pnf|9?~$H  
//if(nThreadID == 1) udw>{3>  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); : L}Fm2^  
} t~_j+k0K#  
`zf,$67>1  
+,oEcCi  
Utility.log("Thread " + nThreadID + " is over!"); wxC&KrRF  
bDownOver = true; (4:&tm/;  
//nPos = fileAccessI.write (b,0,nRead); K>%}m,  
} +5:Dy,F =  
catch(Exception e){e.printStackTrace ();} ~V#MI@]V~  
} a^:on?:9  
} DJ&ni`  
3JhT  
f@JMDJ  
//打印回应的头信息 UqVcN$^b  
public void logResponseHead(HttpURLConnection con) GM]" $  
{ q{4W@Um-  
for(int i=1;;i++) BY*{j&^  
{ $y%X#:eLJ  
String header=con.getHeaderFieldKey(i); }5_[t9LX  
if(header!=null) :mP%qG9U  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }~B@Z\`O  
Utility.log(header+" : "+con.getHeaderField(header)); h?t#ABsVK  
else ~nQ=iB  
break; K<k!sh   
} 7kiZFHV  
} Ih Yso7g  
F+ ,eJ/]  
~yX8p7qr  
public void splitterStop() 1P8XVI'  
{ *[VO03  
bStop = true; QuB`}rfLf  
} ~rnbuIh  
T"h@-UcTl  
.\Z/j  
} kHWW\?O  
2EO WbN}M  
O_v8R7 {  
/* +/"Ws '5E  
**FileAccess.java IBP3  
*//文件访问(定位,写) y4N8B:j%  
package NetFox; cy_'QS$W   
import java.io.*; j 3/ I =  
hk5[ N=  
RN, 5>.w  
public class FileAccessI implements Serializable{ 8>R 75 dw  
gKPqWh  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uUhqj.::<Y  
RandomAccessFile oSavedFile; 6[.#B!;9  
long nPos;  f$7Xh~  
#|92 +  
k4n 4 BL  
public FileAccessI() throws IOException 2SjH7 '  
{ p :v'"A}  
this("",0); 4n9".UHh  
} !O*'mX  
`EBI$;!  
%-nYK3  
public FileAccessI(String sName,long nPos) throws IOException X  jPPgI  
{ J\@ r ~x5G  
oSavedFile = new RandomAccessFile(sName,"rw"); ,0hk)Vvr3  
this.nPos = nPos; E =*82Y=B  
oSavedFile.seek(nPos); xX !`0T7Y  
} z_i (o  
kv!QO^;^Y  
w"PnN  
public synchronized int write(byte[] b,int nStart,int nLen) f6of8BOg  
{ b(E}W2-t  
int n = -1; ^uWPbW&/q  
try{ @p$Nw.{'  
oSavedFile.write(b,nStart,nLen); l1M %   
n = nLen; AfAlDM'  
} mp'Z.4  
catch(IOException e) Yg<L pjq5X  
{ Ri   
e.printStackTrace (); #oYPe:8|m  
} 6D\$K  
B5A/Iv)2  
w$)NW57[|  
return n; C {*' p+f  
} {+3 `{34e  
h]+UK14m  
*jf%Wj)0M  
} 21T#NYfew  
MQ#nP_i  
mhNX05D  
/* ,J$XVvwxF  
**SiteInfoBean.java n%S%a >IQj  
*/ B,5kG{2!  
package NetFox; ; _K3/:  
&E?TR A# E  
WR.>?IG2E  
public class SiteInfoBean { XsEo tW  
mG*ER^Y@D  
IDY2X+C#U  
private String sSiteURL; //Site's URL !,cL c}a  
private String sFilePath; //Saved File's Path QomihQnc  
private String sFileName; //Saved File's Name : MEB] }  
private int nSplitter; //Count of Splited Downloading File QM) ob  
 5(\H:g\z  
|Wg!> g!  
public SiteInfoBean() E]P7u"1  
{//nSplitter的缺省值为5 2JhE`EVH  
//default value of nSplitter is 5 X T<SR]  
this("","","",5); "!B\c9q  
} gTQc=,3l3  
FKH_o  
KY'x;\0 g  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &v/>P1Z G  
{ |muZv!,E  
sSiteURL= sURL; vf@toYc[E  
sFilePath = sPath; iAr]Ed"9|  
sFileName = sName; yno X=#`  
this.nSplitter = nSpiltter; 5-RA<d#  
%HD0N&  
W]oILL"d  
} AX]cM)w  
OQJ#>*?  
6QYHPz  
public String getSSiteURL() ujf]@L?  
{ 8Q(A1U  
return sSiteURL; so>jz@!EE  
} ]@6L,+W"  
8~}~ d}wW  
}rQ0*h  
public void setSSiteURL(String value) JKF/z@Vbe\  
{ "!9FJ Y  
sSiteURL = value; !"LFeqI$lr  
} 0O!A8FA0  
|4j'KM;U  
bIXD(5y  
public String getSFilePath() RgD%pNhI  
{ 3(,c^F  
return sFilePath; bs_< UE  
} %D49A-R  
Y_FQB K U  
4g)$(5jI}  
public void setSFilePath(String value) !DkIM}.  
{ }a"koL  
sFilePath = value; -7IRlP&  
} +&4@HHU{G  
&U_T1-UR2  
mM2DZ^"j(  
public String getSFileName() EEP&Y?  
{ Od+nBJ   
return sFileName; ~hb;kc3  
} 8 +mW  
&e3pmHp'  
T`2a)  
public void setSFileName(String value) A\})H  
{ 7?ILmYBw  
sFileName = value; 0C4Os p  
} AbL(F#{  
}p>l,HD  
L>n^Q:M  
public int getNSplitter() %RIlu[J  
{ Rxq4Diq5k  
return nSplitter; gbu*6&j9  
} q\/xx`L  
f C+tu>=  
+fN2%aC  
public void setNSplitter(int nCount) ?!u9=??  
{ G6bvV*TRi  
nSplitter = nCount; .\+c{  
} |*g\-2j{  
} tN;^{O-(V  
`0`#Uf_/$  
iSNbbu#  
/* 0E7h+]bh|  
**Utility.java E <N%  
*/ ]Na;b  
package NetFox; Ch)E:Dvq6  
: cPV08i  
fS3%  
public class Utility { >@EwfM4[e  
+4F; m_G6  
5`QfysR5  
public Utility() y]g5S-G  
{ `( 'NH]^  
l%qfaU2  
} x Kv N  
} em2Tet  
JyePI:B&)j  
//线程睡眠 L7"<a2J  
public static void sleep(int nSecond) C'PHbo:  
{ lNMJcl3  
try{ 2RdpVNx\y  
Thread.sleep(nSecond); tILnD1q  
} Ym#io]  
catch(Exception e) TA+#{q+a  
{ "?6R"Vk?:  
e.printStackTrace (); 3}B-n!|*  
} OI:T#uk5  
} 4{h^O@*g  
|M EJ)LE7  
//日志 @h\i<sh!^  
public static void log(String sMsg) E)]emeG d  
{ _8 l=65GW  
System.err.println(sMsg); Q6n8,2*  
} ~ujg250.L  
[6?x 6_M  
EcPvE=^c  
public static void log(int sMsg) +&* >FeJY  
{ a YY1*^  
System.err.println(sMsg); u4xJ-Vu  
} lUiO|  
} `FK qVd  
'i;ofJ[.c  
o3`0x9{  
/* 9y*(SDF  
**TestMethod.java r<;Y4<,BZ  
*/ F#o{/u?T  
package NetFox; 5a/3nsup5  
\5b<!Nl  
f5R%F ~  
public class TestMethod { &<) _7?  
wKJK!P  
fN 1:'d  
public TestMethod() 9Dyw4'W.N  
{ ///xx/weblogic60b2_win.exe  LNvkC4  
try{ R(2MI}T  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6wb M$|yFj  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nTsPX Tat  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3]>YBbXvE  
fileFetch.start(); }'\M}YM  
} E8o9ufj3  
catch(Exception e){e.printStackTrace ();} Y3xEFqMU  
4-\4G"4  
/sVmQqVY  
} K,*IfHi6[  
k,y#|bf,Y  
mN#&NA  
public static void main(String[] args) K4^B~0~  
{ ?hW(5]p|  
new TestMethod(); '=IuwCB|;  
} G+iJS!=  
} B,Jn.YX  
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