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)); ,j wU\xo`C
} .#R\t 7m%
for(int i=0;i<nEndPos.length-1;i++) EqzS={Olj
{ J{' u
nEndPos = nStartPos[i+1]; 5VIpA
} |D)NPN&
nEndPos[nEndPos.length-1] = nFileLength; 9v)p0
} ul~>eZ
} PT4Xr=z =
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L%`~`3%n-
//启动子线程 jI@0jxF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -e#YWMo(
for(int i=0;i<nStartPos.length;i++) Be+'&+
{ {\22C `9t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B]dHMLzl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \7Hzj0hSi
nStartPos,nEndPos,i); ey<u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v'*
fileSplitterFetch.start(); "!<Kmh5
} 6'W79
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~rEU83
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NGB%fJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %Qc#v$;+J
nEndPos = " + nFileLength); KquHc-fzqr
// fileSplitterFetch[nPos.length-1].start(); ^7v}wpwX\
Z"#ysC
tr"iluwGc
//等待子线程结束 >XP]NY}Po[
//int count = 0; i'J.c4
//是否结束while循环 kRNr`yfN
boolean breakWhile = false; $wU.GM$t~
c38RE,4U
}Q_IqI[7
while(!bStop) yrO'15TB
{ FT73P0!8.
write_nPos(); i_ws*7B<
Utility.sleep(500); z<c^<hE:l
breakWhile = true; %Rv&VFg
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for(int i=0;i<nStartPos.length;i++) %)*!(%\S*3
{ W"4E0!r
if(!fileSplitterFetch.bDownOver) {EbR =
{ STu!v5XY}-
breakWhile = false; g[Ah> 5
break; {55{YDqx
} 6XUcJ0
} r=4'6!
if(breakWhile) ]]@jvU_?kS
break; !>b>"\b
u7G@VZ Ux5
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//count++; OQaM47"
//if(count>4) c#nFm&}dm
// siteStop(); .:Bjs*
} wl2rw93
/A\'_a|
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System.err.println("文件下载结束！"); (:2:_FL
} VaQ>g*(I
catch(Exception e){e.printStackTrace ();} ;%2/
} m8$6FN
7CYu"+Ea
&0SGAJlec
//获得文件长度 Je2o('MA
public long getFileSize() 0z/tceW'F
{ is?`tre\P
int nFileLength = -1; 85Q2c
try{ KL#F5\ E
URL url = new URL(siteInfoBean.getSSiteURL()); 53P\OG^G`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q6Y1Jr">X
httpConnection.setRequestProperty("User-Agent","NetFox"); ZgF-.(GV
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9>u2; 'Ls
int responseCode=httpConnection.getResponseCode(); &#v^y3r
if(responseCode>=400) SSycQ4[{o
{ } IFZ$Y
processErrorCode(responseCode); xy46].x-
return -2; //-2 represent access is error wx -NUTRim
} z %{>d#rw
Z"'rc.>a
[VIdw92
String sHeader; </tiNc
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GjE/!6b
for(int i=1;;i++) |M#b`g$JO,
{ iN+Dmq5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Tk$rwTCl
//Utility.log(in.readLine()); !I]fNTv<
sHeader=httpConnection.getHeaderFieldKey(i); W=}l=o!G.
if(sHeader!=null) p.TR1BHw
{ \$^z.
if(sHeader.equals("Content-Length")) \lCr~D5
{ &}32X-~y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^i_mGeu
break; ?;>s<
} rtv\Pf|
} xb0hJ~e
else ^tsIgK^9H
break; *!%y.$\cE
} K6~N{:.s
} ??=CAU%\
catch(IOException e){e.printStackTrace ();} /ivt8Uiw
catch(Exception e){e.printStackTrace ();} ,,mkB6;
GV6!`@<
W*;~(hDz
Utility.log(nFileLength); 'IP'g,o++
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;j=/2vU~@
return nFileLength; '@2pOq
} 5[`!\vCiZ
\6)l(b;
5fv eQI~!
//保存下载信息（文件指针位置） g[*+R9'
private void write_nPos() #tN)OZA
{ (S0MqX*
try{ 'Fo*h6=
output = new DataOutputStream(new FileOutputStream(tmpFile)); #<0%_Ca
output.writeInt(nStartPos.length); c.m '%4
for(int i=0;i<nStartPos.length;i++) +`kfcA#pi
{ 5FtbZ1L
// output.writeLong(nPos); K8Gc5#OF
output.writeLong(fileSplitterFetch.nStartPos); |@]J*Kh
output.writeLong(fileSplitterFetch.nEndPos); yeKzI~
} k6ERGQ9|I
output.close(); Z/sB72K1
} P[n`X
catch(IOException e){e.printStackTrace ();} 3m#v|52oj
catch(Exception e){e.printStackTrace ();} Z66akr
} r1EccY
w4:S>6X
]p(+m_F
//读取保存的下载信息（文件指针位置） !1C3{
private void read_nPos() T=:O(R1*0
{ b=:AFs{
try{ N/DcaHFYo
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yJWgz`/L
int nCount = input.readInt(); 15r,_Gp8
nStartPos = new long[nCount]; hdW",Bf'
nEndPos = new long[nCount]; }+#-\a2
for(int i=0;i<nStartPos.length;i++) qg:R+`z
{ *GbC`X)
nStartPos = input.readLong(); # ,u7lAz
nEndPos = input.readLong(); Y"D'|i
} +8."z"i3lE
input.close(); r|:|\"Yk
} A`Z!=og=
catch(IOException e){e.printStackTrace ();} ]7O)iq%
catch(Exception e){e.printStackTrace ();} ^)rX27!G
} <?&GBCe
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l^:m!SA_
private void processErrorCode(int nErrorCode) LVq3R 8A
{ :HYqm*v;W
System.err.println("Error Code : " + nErrorCode); bWt>tEnf
} vI{JBWE,S
W tnZF]1:u
*;Dd:D9
//停止文件下载 1s-k=3)
public void siteStop() x6* {@J&5*
{ kCL)F\v"iT
bStop = true; T_\HU*\
for(int i=0;i<nStartPos.length;i++) N)lzX X
fileSplitterFetch.splitterStop(); w}G2m)(
m/|>4~
(Z=ziopDE
} M]!R}<]{
} as)2ny!u
//负责部分文件的抓取 {0q;:7Bt
**FileSplitterFetch.java 49bzHEqZ
*/ p H5IBIf'
package NetFox; S+R<wv,6
vpFN{UfD
j,80EhZ
import java.io.*; jx!)N>
import java.net.*; ?1?^>M
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] ^tor
public class FileSplitterFetch extends Thread { AT<gV/1l
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sD1L P
String sURL; //File URL ;y%lOYm
long nStartPos; //File Snippet Start Position F_/]9tz?;
long nEndPos; //File Snippet End Position _K)B
int nThreadID; //Thread's ID zawU
boolean bDownOver = false; //Downing is over RU,f|hB4
boolean bStop = false; //Stop identical e,={!P"f
FileAccessI fileAccessI = null; //File Access interface J|sX{/WT
WiH%URFB
m( C7Fa
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S]KcAz(fX
{ @BbZ(cZ*
this.sURL = sURL; i@6MO'y
this.nStartPos = nStart; xQ>c.}J/i
this.nEndPos = nEnd; wp-5B= #:{
nThreadID = id; )pjd*+V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;o,t*
} b3wE8Co
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t LdBnf
public void run() a^'1o9
{ $yIcut7
while(nStartPos < nEndPos && !bStop) VQZ3&]o
{ k;3Bv 6
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(sW:^0p
try{ g.kpUs
URL url = new URL(sURL); k~>9,=::d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DifRpj I-0
httpConnection.setRequestProperty("User-Agent","NetFox"); N;>>HN[bBP
String sProperty = "bytes="+nStartPos+"-"; fGcAkEstT!
httpConnection.setRequestProperty("RANGE",sProperty); d@b0z$<s
Utility.log(sProperty); tE]g*]o
,ZJI]Q=!
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InputStream input = httpConnection.getInputStream(); VCiJ]$`M
//logResponseHead(httpConnection); zid?yuP
#E2`KGCzW
c,Zs. kC
byte[] b = new byte[1024]; {p|OKf
int nRead; ;Z-Cn.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 79~,KFct
{ ZFOYYht
nStartPos += fileAccessI.write(b,0,nRead); qDqIy+WR
//if(nThreadID == 1) kI<C\*N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O4@Ki4f3A%
} qRJg/~_h{
$G"PZ7
iVd*62$@$
Utility.log("Thread " + nThreadID + " is over!"); ?|%^'(U}
bDownOver = true; U_ V0
//nPos = fileAccessI.write (b,0,nRead); MfJk`-%~
} 6.6~w\fR8
catch(Exception e){e.printStackTrace ();} &{7n
} L4zSro:Si
} 3Ym5SrKK
uw LT$
$e+@9LNK
//打印回应的头信息 [])M2_
public void logResponseHead(HttpURLConnection con) :)c >5
{ Q0gO1T
for(int i=1;;i++) ,vrdtL
{ "@gJ[BL#
String header=con.getHeaderFieldKey(i); hAOXOj1
if(header!=null) $.QnM
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kNI m90,g
Utility.log(header+" : "+con.getHeaderField(header)); .Y&_k
else enF.}fo]
break; ?p. dc~tZ
} vPi\ vU{
} Ufv{6"sH
!}"npUgE
Al3Hu-Hf;`
public void splitterStop() Wv77ef
{ D,mFme
bStop = true; X-3L4@T:?
} 1|;WaO1Q
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} cK(}B_D$
kX'1.<[
(dpBGt@
/* Fy`VQ\%7t
**FileAccess.java zO2<Igb
*//文件访问(定位，写) ,<R/x[
package NetFox; }C/}8<
import java.io.*; GE Xz)4[
e:AB!k^xp$
*X*D, VY
public class FileAccessI implements Serializable{ O~">-'f
t82Bp[t
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :7W5R
RandomAccessFile oSavedFile; eP&K]#
long nPos; `gfK#0x#
5c{=/}Y
EQ?4?
public FileAccessI() throws IOException ^nkwT~Bya
{ 66:|)
this("",0); r\@"({q}_-
} /W:}p(>4a
@faf
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public FileAccessI(String sName,long nPos) throws IOException |8`}yRsQ
{ %04>R'mN
oSavedFile = new RandomAccessFile(sName,"rw"); Y +HVn0~qz
this.nPos = nPos; {EW}Wd
oSavedFile.seek(nPos); }mu8fm'
} dam.D.o"
U!3nn#!yE
6XFO@c}d
public synchronized int write(byte[] b,int nStart,int nLen) dMRwQejY{7
{ p"q-sMYl
int n = -1; i;6\tK"!
try{ fkRb;aIl
oSavedFile.write(b,nStart,nLen); IdzF<>;W
n = nLen; \Q^\z
} q?}G?n4
catch(IOException e) A.35WGu&:
{ gxU(&
e.printStackTrace (); (>WV)
} *eUL1m8Y
Qksw+ZjY#{
;1(OC-2>d
return n; DgClN:Hw
} HeSnj-mtr}
7T4rx53
_AVCh)Zb
} 'v6Rd)E\z
6TfXz2D'J
>f`}CLsY
/* KgAc0pz{7H
**SiteInfoBean.java AuO%F YKY
*/ 07/5RFmJ
package NetFox; -BEPpwb<g
F4bF&% R
<=A&y5o
public class SiteInfoBean { _QXo4z!a8
QXXcJc~
c^Wm~"r
private String sSiteURL; //Site's URL HK2`.'D
private String sFilePath; //Saved File's Path y)s/\l&
private String sFileName; //Saved File's Name ;R2(Gb
private int nSplitter; //Count of Splited Downloading File C$,S#n@
Xk7zXah
zoUW}O
public SiteInfoBean() )h+JX8K)l
{//nSplitter的缺省值为5 "T~Ps$
//default value of nSplitter is 5 KVQZ
this("","","",5); I,
} !Y\hF|[z
HnOF_Twq
/Zm@.%.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /f0_mi,bD
{ _fMooI)U1
sSiteURL= sURL; |d{(&s}
sFilePath = sPath; ~PoGuj2wA
sFileName = sName; 0&5}[9?V'
this.nSplitter = nSpiltter; Or_9KX2
}$$b6G
3FX`dZ
} N>]u;HjH
q!O~*
V!ajD!00
public String getSSiteURL() (MxLw:AV
{ 9wtl|s%A%
return sSiteURL; Y~Jq!
} sjaG%f&h
5R o5Cg~
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public void setSSiteURL(String value) 8,B9y D
{ Nc;7KMOIA
sSiteURL = value; ](Sp0t
} P!]DV$o
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@|d|orMC
public String getSFilePath() 9k$uo_i'
{ { ET+V
return sFilePath; :;7qup
} /iukiWeW
F,lQj7
lzwr]J%|?
public void setSFilePath(String value) 9ykmz (
{ sq<y2j1oF
sFilePath = value; }*BY!5
} !PQ@"L)p
nY~CAo/:
<Ft.{aNq$c
public String getSFileName() ,l@hhaLm?
{ ^8fO3<Jg
return sFileName; T.K$a\/{,
} ,u\M7,a^
@Z|cUHo
A Ys<IMQ
public void setSFileName(String value) e@I?ESZ5
{ Y$,]~Qzq
sFileName = value; QTP1u
} <X;y 4lPZ
o9Agx{'oV
*/Y@:Sjf
public int getNSplitter() ]INbRytvc
{ v"bOv"!al
return nSplitter; yWX:`*GV
} ^M,Q<HL
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public void setNSplitter(int nCount) /yH:ur
{ C\fc 4
nSplitter = nCount; *[ A%tj%
} [!DLT6Qk
} F%< 0pi
rV1JJ.I
\hm=AGI0
/* _A%z^&k(i
**Utility.java %q:V
*/ ob0clJX
package NetFox; B04Br~hel*
~j8x"
ph3[}><6
public class Utility { am@\$Sa4
qwVpGNc45
;O.U-s
public Utility() ``zg |h
{ ,.F,]m=
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'n.ATV,
} pU}>}
?hmj0i;XC
//线程睡眠 A$%%;O
public static void sleep(int nSecond) B_@>HZ\&
{ 7gPkg63
try{ zvD$N-#`p
Thread.sleep(nSecond); c\-I+lMBi
} N/^r9Nu
catch(Exception e) -a/5
{ D'A)H
e.printStackTrace (); ("IRv>} 0
} C2!POf;GdN
} qzmY]N+w|
8=<d2u'
//日志 t7R;RF
public static void log(String sMsg) y37n~~%
{ ]D(%Ku,O%
System.err.println(sMsg); DBVe69/S
} @(oz`|*
8l)^#"ySA
$ V}s3
public static void log(int sMsg) 4qiG>^h9
{ &Du!*V4A
System.err.println(sMsg); t;ggc{
} VNA VdP
} o6oZk0
Rl$NiY?2
ud!iy
/* N}zQ)]xz+r
**TestMethod.java lq+FH&
*/ -l$]>J~
package NetFox; a i}8+L8-
0*,r
z<s]Z
public class TestMethod { pbju;h)O!|
y{5ZC~Z<!
Wh 8fC(BE
public TestMethod() ?hsOhUs(5
{ ///xx/weblogic60b2_win.exe e7 5*84
try{ "y>l2V,4j%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -/KVZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2hu;N
SiteFileFetch fileFetch = new SiteFileFetch(bean); :DQHb"(
fileFetch.start(); (x#4BI}L9)
} mp!6MOQ
catch(Exception e){e.printStackTrace ();} A1Rt
ezy0m}@
@[.%A;E4
} l}Jf;C*j1z
m9xO& @#vx
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public static void main(String[] args) 36.L1!d)pE
{ =U3!D;XP
new TestMethod(); k`kmmb>
} "-(yZigQ
} ADlPdkmym
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