http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); #`/bQ~s
} sNL+F
for(int i=0;i<nEndPos.length-1;i++) f[x~)=
{ s~L`53A
nEndPos = nStartPos[i+1]; $( S*GF$S
} y)P&]&"?
nEndPos[nEndPos.length-1] = nFileLength; nt7|f,_J
} ;:P7}v fz!
} d>UnJ)V}
$nj\\,(g
V]Sgx00;
//启动子线程 >wA+[81[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vruD U#
for(int i=0;i<nStartPos.length;i++) -(!uC+BZX
{ 4bnt=5]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *t^eNUA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RF:04d
nStartPos,nEndPos,i); \UOm]z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h{I`7X
fileSplitterFetch.start(); gt'*B5F(
} a_Jb>}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *m*`}9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Wu,S\!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }7%9}2}Iw
nEndPos = " + nFileLength); kL|\wci
// fileSplitterFetch[nPos.length-1].start(); rR\;G2p)
]a M-p@
sa G8g
//等待子线程结束 }"hW b(
//int count = 0; hqL+_|DW
//是否结束while循环 8yn4}`Nc@
boolean breakWhile = false; /N>} 4Ay
)#a7'Ba
7SaiS_{:
while(!bStop) WVOoHH
{ 0Q7MM6
write_nPos(); [P{a_(
Utility.sleep(500); )AI?x@
breakWhile = true; 40u7fojg2
!~)90Z!
\0nlPXk?G
for(int i=0;i<nStartPos.length;i++) h(nj,X+
{ >zQOK-
if(!fileSplitterFetch.bDownOver) RpYcD
{ T<P0T<
breakWhile = false; Bhe{L?}0
break; fH[Wkif
} )9B:Y;>)
} FNC[59
if(breakWhile) #ra*f~G
break; L!,d"wuD
2L:$aZ
NEw$q4
//count++; GV5qdD(
//if(count>4) a$}NW.
// siteStop(); +pz}4M`
} *jE;9^
->h5T%sn
h,t:]
System.err.println("文件下载结束！"); QXs8:;T
} @MOCug4
catch(Exception e){e.printStackTrace ();} xz8G}Ku
} FIS "Z(
{rDq_^
LL.x11o3
//获得文件长度 pw\P<9e=
public long getFileSize() f0DK>L
{ a~opE!|m
int nFileLength = -1; BZ+;n |<r
try{ 6Hk="$6K
URL url = new URL(siteInfoBean.getSSiteURL()); ~>g+2]Bn>$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \x(^]/@
httpConnection.setRequestProperty("User-Agent","NetFox"); hO \/
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5$%XvM
int responseCode=httpConnection.getResponseCode(); doR4nRl9
if(responseCode>=400) '#q4Bc1
{ L5f$TLw h;
processErrorCode(responseCode); ^s-25 6iI
return -2; //-2 represent access is error JhP\u3 QE
} k"0;D-lTZ>
0e16Ow6\!1
DW>ES/B8$(
String sHeader; [EOVw%R
8I.VJ3Q
JYJU&u
for(int i=1;;i++) wXbsS)#/
{ N}x9N.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xb,T{.3@
//Utility.log(in.readLine()); JNi=`X&A
sHeader=httpConnection.getHeaderFieldKey(i); "}zt`3
if(sHeader!=null) +rc SL8C
{ C6]OAUXy:F
if(sHeader.equals("Content-Length")) $gvr -~
{ X{\jK]O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S)7/0N79A
break; :$%>4+l
} Qnt5HSSt
} v@n_F
else |##GIIv;i
break; t,HFz6
} .Y\EE;8%
} qybxXK:
catch(IOException e){e.printStackTrace ();} ^2C>L}
catch(Exception e){e.printStackTrace ();} /iG7MC\`
p!DP`Ouc3\
4TZ cc|B5
Utility.log(nFileLength); 8:dQ._#v
q.W>4 k
p$XKlg&
return nFileLength; ?lKhzH.T
} prrT:Y
nB] Ia?
wxdyF&U n
//保存下载信息（文件指针位置） 24B<[lSK
private void write_nPos() iKAusWj
{ WD.U"YI8y
try{ !%[S49s
output = new DataOutputStream(new FileOutputStream(tmpFile)); ].mqxf
output.writeInt(nStartPos.length); tTuX\;G
for(int i=0;i<nStartPos.length;i++) =J/FJb
{ {dzoEM[ 1s
// output.writeLong(nPos); =;ICa~`C;
output.writeLong(fileSplitterFetch.nStartPos); L'E^c,-x~
output.writeLong(fileSplitterFetch.nEndPos); fYX<d%?7
} >cgpajx*
output.close(); yWb4Ify
} rQr!R$t/[
catch(IOException e){e.printStackTrace ();} q-_' W,
catch(Exception e){e.printStackTrace ();} GBQn_(b9I
} /tj$luls5
;;#`#v
tj5giQ3DG)
//读取保存的下载信息（文件指针位置） z7T0u.4Ss
private void read_nPos() r,NgG!zq<
{ 6N" l{!
try{ 3WUH~l{UJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,:GN;sIXg
int nCount = input.readInt(); *y]+dK&-
nStartPos = new long[nCount]; LW:1/w&pv
nEndPos = new long[nCount]; ^+/kr/
for(int i=0;i<nStartPos.length;i++) %l!xkCKA
{ {x@|VuL=
nStartPos = input.readLong(); :]II-$/8
nEndPos = input.readLong(); Ed-M7#wY
} D/ Dt
input.close(); ,={t8lN
} {' 5qv@3
catch(IOException e){e.printStackTrace ();} wT_h!W
catch(Exception e){e.printStackTrace ();} $kPHxD!"
} a9Y5
=.Tv)/ea
lFq{O;q7}
private void processErrorCode(int nErrorCode) |FNCXlgZ
{ !#N\b
System.err.println("Error Code : " + nErrorCode); Nneo{j
} go'j/4Tp
DBgMC"_
=RsXI&&vh
//停止文件下载 >I'%!E;
public void siteStop() [hh/1[
{ l=={pb
bStop = true; >)**khuP7
for(int i=0;i<nStartPos.length;i++) ELD!{bMT
fileSplitterFetch.splitterStop(); w0J|u'H
#wR;|pN
Zv!{{XO2;
} GbZ;#^S
} zT9JBMNE:
//负责部分文件的抓取 j*R,m1e8
**FileSplitterFetch.java K8[DZ)rO;Z
*/ 1hmc,c
package NetFox; %X1x4t]
z`3( ,V
(z7+|JE.
import java.io.*; nJFg^s1
import java.net.*; B[o`k]]
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tWPO]3hW
public class FileSplitterFetch extends Thread { {D`T0qPT[
r4XH =
0L-!! c3
String sURL; //File URL 5iX! lAFJ
long nStartPos; //File Snippet Start Position cP>o+-)
long nEndPos; //File Snippet End Position m$2<`C=
int nThreadID; //Thread's ID MuI2?:~:*4
boolean bDownOver = false; //Downing is over .*/Fucr
boolean bStop = false; //Stop identical E6MA?Ax&=
FileAccessI fileAccessI = null; //File Access interface TnH\O$
SNpi=K!yn
wdas1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3HC
{ }}{Yw
this.sURL = sURL; 1KE:[YQ1
this.nStartPos = nStart; H)(jh
this.nEndPos = nEnd; gP}+wbk
nThreadID = id; rZ03x\2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -ysn&d\rV
} 7jG(<!,
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dK9Zg,DZL
public void run() ]uh3R{a/
{ LHYLC>J
while(nStartPos < nEndPos && !bStop) \2v"YVWw
{ nv/[I,nw
Gh( A%x)
;0%OB*lcgE
try{ iThSt72
URL url = new URL(sURL); 2I'~2o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kUl
httpConnection.setRequestProperty("User-Agent","NetFox"); 6g:|*w
String sProperty = "bytes="+nStartPos+"-"; !q"cpL'4
httpConnection.setRequestProperty("RANGE",sProperty); uaPx"
Utility.log(sProperty); ^TdZ*($5
/Lf6WMit
n# 7Pr/*0
InputStream input = httpConnection.getInputStream(); :#t*K6dz
//logResponseHead(httpConnection); a[!%Ld
7(a2L&k^
t0E51Ic@
byte[] b = new byte[1024]; B4H!5b
int nRead; !nf-}ze{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t+Bf#:
{ :!TIK1
nStartPos += fileAccessI.write(b,0,nRead); M[]A2'fS
//if(nThreadID == 1) 5"KlRuv%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E8[T
} ]+Ixi o
\,G#<>S
&2.u%[gO[q
Utility.log("Thread " + nThreadID + " is over!"); (R}ii}&
bDownOver = true; 2t#L:vY
//nPos = fileAccessI.write (b,0,nRead); 9J-b6,
} %VNlXHO.
catch(Exception e){e.printStackTrace ();} # TkR
} 3R$Z[D-
} ps|)cW3`
kGYTl,A{
ro~+j}*
//打印回应的头信息 .?W5{U
public void logResponseHead(HttpURLConnection con) &:#h$`4
{ =6nD sibf
for(int i=1;;i++) 5jcte< 5I_
{ S=|@L<O
String header=con.getHeaderFieldKey(i); L@Nu/(pB=
if(header!=null) ~aK?cP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qt e>r
Utility.log(header+" : "+con.getHeaderField(header)); qOhO qV
else {p<Zbm.
break; ()T[$.(
} 15\Ph[6g
} ^%T7.1'x
&"Ux6mF-"
6=GZLpv
public void splitterStop() j7QX,_Q
{ ~p1EF;4#
bStop = true; X@2-*so<
} J;Rv ~<7
Zo-$z8
\E1U@6a
} ,L> ar)B
= "ts`>
+a@GHx4-
/* }WLh8i?_
**FileAccess.java dI'SwnR
*//文件访问(定位，写) JH,/jR
package NetFox; sYSLmUZ{
import java.io.*; l:B;zi`)oB
L:nXWz
$^/0<i$
public class FileAccessI implements Serializable{ LaFZ?7@|}
22hSove.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 knp>m,w
RandomAccessFile oSavedFile; cR7wx 0Aj
long nPos; 6=_~0PcY
l:|D,q
1%[_`J;>Z
public FileAccessI() throws IOException QbFHfA2Ij
{ q<vf,D@{ !
this("",0); I&yVx8aH}
} 4<,|*hAT
;F:fM!l=
vsB*rP=
public FileAccessI(String sName,long nPos) throws IOException ;i uQ?MR3
{ >pyj]y^3
oSavedFile = new RandomAccessFile(sName,"rw"); Njc%_&r
this.nPos = nPos; dhPKHrS
oSavedFile.seek(nPos); ]$-cMX
} 8TV;Rtl
ed 59B)?l
:;;E<74e i
public synchronized int write(byte[] b,int nStart,int nLen) DPgm%Xq9(!
{ 6c4&VW
int n = -1; x+5k <Xi}
try{ SUCUP<G
oSavedFile.write(b,nStart,nLen); Pz_Oe,{.I
n = nLen; /lhz],w
} }Rvm &?~O
catch(IOException e) j1$8#/r;c
{ RF}X ER
e.printStackTrace (); j-@kW'K
} <E|s\u
C2U~=q>>
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return n; 0Wvq>R.(]7
} #EO1`9f48x
e9pOisZ;8
G`h+l<
} 'vV$]/wBF
jF ^5}5U
}alj[)
/* <~emx'F|
**SiteInfoBean.java }3 m0AQ;K
*/ I`RBj`IF
package NetFox; vE, 37
rnFM/GAy
kfb/n)b'
public class SiteInfoBean { ]DG?R68DQ
}ucIH@U{
9-1#( Y6S
private String sSiteURL; //Site's URL \0;(VLN'U
private String sFilePath; //Saved File's Path *O$CaAr\s
private String sFileName; //Saved File's Name f|EUqu%E
private int nSplitter; //Count of Splited Downloading File i%Z2wP.o
;^u*hZN[Up
q z&+=d@
public SiteInfoBean() t G.(flW,
{//nSplitter的缺省值为5 m4w')r~
//default value of nSplitter is 5 )emOKS
this("","","",5); F!!N9VIC
} o5o^TW{
~,6b_W p/
5AeQQU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) sd re#@n}
{ l.)}t)my}
sSiteURL= sURL; o}Cq.[G4k
sFilePath = sPath; 4EP<tV
sFileName = sName; 1$lh"fHU
this.nSplitter = nSpiltter; 1nhtM
5~ 'Ie<Y_
*ZSdl0e
} :\~+#/=:
~i;fDQ&!
zdun,`6
public String getSSiteURL() 3:/'n
{ 9%)=`W
return sSiteURL; y %8op:'
} H5>hx{
9.O8/0w7LV
k,Qskd-N]
public void setSSiteURL(String value) :c[n\)U[aa
{ ks;%*d
sSiteURL = value; `\Ku]6J]5
} .ae O}^
&O\(;mFc
XEM'}+d
public String getSFilePath() +V862R4,o
{ q~K(]Ya/
return sFilePath; !G5a*8]
} &F$:Q:* *
d5I f"8`@
B#%;Qc
public void setSFilePath(String value) V_n<?9^4
{ X26
sFilePath = value; f3*?MXxb16
} K!AAGj`
/(C~~XP)
7sNw
public String getSFileName() qf)$$qi
{ vC;]jJb:
return sFileName; >XW*T5aUA
} $K~LM8_CKy
H(^bC5'
$3+PbYY
public void setSFileName(String value) n";02?@F
{ ,"}Rg1\4t
sFileName = value; *~$~yM/~3U
} { >{B`e`$
_A_ A$N~9
p\vMc\
public int getNSplitter() 2 -!L _W(
{ Ft JjY@#
return nSplitter; M&Y .;
} 9~IQw#<
0"k|H&
3B0lb"e
public void setNSplitter(int nCount) [t]X/O3<
{ f2)XP$:
nSplitter = nCount; i=FQGWAUu
} `ejUs]SR
} v`q\6i[-
XkKC!
(kBP(2V
/* ?|;yVew
**Utility.java 5-u=o)>
*/ 72TI
package NetFox; ]Al;l*yw
k5d\w@G"~
J<n+\F-s
public class Utility { ;+"f
LS>G4 ]
wgeNs9L
public Utility() pj|pcv^
{ >:sUL<p
tS# `.F~y
5 +9Ze9
} ~89P[$6
5__+_hO ;3
//线程睡眠 X+8B!F
public static void sleep(int nSecond) |tMn={
{ /x@RNdKv
try{ Vsq8H}K
Thread.sleep(nSecond); DmqX"x%P
} =V+I=rqo
catch(Exception e) <g8K})P
{ (AY9oei>
e.printStackTrace (); ("7M b{
} *mG`_9
} /Poet%XvRx
(3vHY`9
//日志 I XA>`D
public static void log(String sMsg) (n( fI f
{ z;u> Yz+3
System.err.println(sMsg); JeH;v0
} t/i5,le
C2e.2)y
%n0;[sD0A
public static void log(int sMsg) UnWW/]E
{ T0HuqJty
System.err.println(sMsg); m,LG=s
} d4[(8} x$/
} A!W0S
!,$i6gm
1nj(hg
/* qf'm=efRyu
**TestMethod.java uw\1b.r'B
*/ {WN(&eax
package NetFox; [ANuBNF
w6|9|f/
6x{<e4<n
public class TestMethod { Tz&Y]#h_
wy1X\PJjH
?gGt2O1J
public TestMethod() yQS+P8x&|]
{ ///xx/weblogic60b2_win.exe <M?:
try{ |Q~cX!;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w [>;a.$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5,"l0nrk
SiteFileFetch fileFetch = new SiteFileFetch(bean); kW3E =pr
fileFetch.start(); i yYJR
} mbl]>JsQD
catch(Exception e){e.printStackTrace ();} ,n,RFa
I 1d0iU
UAS@R`?cI
} Y+%sBqo@
< O*6T%;
zkM"cb13q/
public static void main(String[] args) .uo.N
{ C=Fzu&N}
new TestMethod(); !4@G3Ae22
} a[bBT@f
} CLD-mx|?
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