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)); W-PZE|<
} -NPkN%h
for(int i=0;i<nEndPos.length-1;i++) (bt]GAxb1
{ ];d:z[\P
nEndPos = nStartPos[i+1]; W>s'4C`
} C9H11g7{
nEndPos[nEndPos.length-1] = nFileLength; =(X'c.%i
} LXC`Zq\
} e-cb?.WU?
gwaC?tf[
/mwr1GU
//启动子线程 un^IQMIh
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _O;~ }N4u
for(int i=0;i<nStartPos.length;i++) fJw=7t-t
{ 56Y5kxmi
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :J`!'{r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C)96/k
nStartPos,nEndPos,i); i>Bi&azx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RpK,ixbtA+
fileSplitterFetch.start(); 7 3z Y^x
} 9H}iX0O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~}0hN]*G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); K^vp(2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", z){UuiUM+=
nEndPos = " + nFileLength); !-RpRRR[Co
// fileSplitterFetch[nPos.length-1].start(); %H}Y]D~R
Mto~ /
!$xEX,vj|W
//等待子线程结束 K}=8:BaUL
//int count = 0; LEngZ~sV/
//是否结束while循环 h!N&gZ[0
boolean breakWhile = false; y]YS2^
wt.{Fqm
Mr NOcx&
while(!bStop) lMzCDx!m
{ N"x\YHp
write_nPos(); ms\/=96F
Utility.sleep(500); ar qLp|
breakWhile = true; y[WYH5&DJ
D ,ZNh1xt
mYjiiql~
for(int i=0;i<nStartPos.length;i++) iRwW>a3/
{ 9h38`*Im;
if(!fileSplitterFetch.bDownOver) u4#~ i0@
{ yFU2'pB
breakWhile = false; NVA`t]gn
break; ):fu
} {.D2ON
} 8cBW] \ v
if(breakWhile) 3Ra\2(bR
break; )|h;J4V
<,X+`m&
]b~2Dap
//count++; YV3TxvXMR
//if(count>4) h,'mN\6t
// siteStop(); Z:Y.":[ Qi
} h GA0F9.U
&8_f'+i0
d+m6-4[_k
System.err.println("文件下载结束！"); C|d!'"p
} (_&V9vat=
catch(Exception e){e.printStackTrace ();} (-'0g@0UA
} UGC|C F2K
N]s7/s
vzyI::f?
//获得文件长度 !Ir1qt8T
public long getFileSize() enbN0
{ (LT\ IJSM
int nFileLength = -1; ;vv!qBl|@
try{ >uchF8)e|
URL url = new URL(siteInfoBean.getSSiteURL()); qtwT#z;Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;[OJ-|Q
httpConnection.setRequestProperty("User-Agent","NetFox"); @maZlw1q
itC *Z6^
%I|+_ z&x
int responseCode=httpConnection.getResponseCode(); hKH$AEHEU}
if(responseCode>=400) Ss<_K>wk
{ d1uG[
processErrorCode(responseCode); 4j@kMe;RjZ
return -2; //-2 represent access is error ySuLt@X
} zA'gb'MmW
-0KbdHIKb'
[zh4W*K_cq
String sHeader; "\zj][sL
_Xk03\n6
L VU)W^
for(int i=1;;i++) n<%=~1iY+
{ *t?~)o7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6N%L8Q
//Utility.log(in.readLine()); SZK)q
sHeader=httpConnection.getHeaderFieldKey(i); 4gv.E 0Fo
if(sHeader!=null) yYG3/Z3u5
{ A1|7(Sow
if(sHeader.equals("Content-Length")) A^4kYOe
{ EBIa%,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vNK`Y|u@
break; fNAo$O4cm
} 0[2BY]`Z.
} (ifqwl62
else (N*<\6kr
break; qr'x0r|<>
} \C+*loLs
} s#+"5&!s
catch(IOException e){e.printStackTrace ();} hs{&G^!jo
catch(Exception e){e.printStackTrace ();} /Oq)3fU e
4Wi8$
9+'@
Utility.log(nFileLength); M}=s3[d(,
#7-kL7 MK]
5D]30
return nFileLength; Fi?32e4KI5
} bRK CY6
wuBlFUSg
z<yNG/M1>U
//保存下载信息（文件指针位置） e>?_)B4
private void write_nPos() 7Ykj#"BZ
{ DnG/ n
try{ &O+sK4P
output = new DataOutputStream(new FileOutputStream(tmpFile)); f!M[awj%
output.writeInt(nStartPos.length); h V|v6 _
for(int i=0;i<nStartPos.length;i++) {z5V{M(|w3
{ vgh^fa!/
// output.writeLong(nPos); j.=UI-&m
output.writeLong(fileSplitterFetch.nStartPos); gqP-E
output.writeLong(fileSplitterFetch.nEndPos); o273|*
} 6m, KL5>W
output.close(); Ism^hyL
} S+) l[0
catch(IOException e){e.printStackTrace ();} YM#
catch(Exception e){e.printStackTrace ();} Qq,i
} 6?1s`{yy
XD$%
fV.A=*1l#
//读取保存的下载信息（文件指针位置） ^eTDD
private void read_nPos() T:K"
{ #D|! .I)
try{ Z/89&Uy`h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h` irO5
int nCount = input.readInt(); >\|kJ?h
nStartPos = new long[nCount]; Cec9#C
nEndPos = new long[nCount]; 5+e>+$2
for(int i=0;i<nStartPos.length;i++) TIcd _>TW
{ ZQ,fm`y\
nStartPos = input.readLong(); #dva0%-1
nEndPos = input.readLong(); /<3;0~#){
} |eHwp
input.close(); g9yaNelDh)
} &\;<t,3A~
catch(IOException e){e.printStackTrace ();} N5pinR5 H
catch(Exception e){e.printStackTrace ();} Xt</ -`
} iGG6Myp-
_u:>1]
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private void processErrorCode(int nErrorCode) pP|,7c5
{ UJee&4C-y
System.err.println("Error Code : " + nErrorCode); 82j'MgGP
} (Oxz'#TX
"C_T]%'Wm
!GlnQ`T
//停止文件下载 5x*5|8
public void siteStop() f,Sth7y
{ ksB
bStop = true; q+YuVQ-fx
for(int i=0;i<nStartPos.length;i++) SQq6X63 \
fileSplitterFetch.splitterStop(); 1^Kj8*O8e
:7 qqjs
I#"t'=9H
} L8K0^~Mk
} 4`'8fe/"
//负责部分文件的抓取 [8,PO
**FileSplitterFetch.java O0@w(L-
*/ 6eOrs-ty
package NetFox; Ze-MAt
NJn&>/vM
aQ(`6DQv
import java.io.*; Z} c'Bm(
import java.net.*; _LJ5o_-N
Hu<p?mF#
BX@pt;$ek7
public class FileSplitterFetch extends Thread { q>^hoW2$C
@bY('gC,
@O@fyAz
String sURL; //File URL {SF[I
long nStartPos; //File Snippet Start Position J&A;#<qY
long nEndPos; //File Snippet End Position M-{*92y& |
int nThreadID; //Thread's ID }X=87ud
boolean bDownOver = false; //Downing is over w+q?T
boolean bStop = false; //Stop identical %oAL
FileAccessI fileAccessI = null; //File Access interface g(mxhD!k
D`~JbKV5@^
d!`lsh@tF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )8[ym/m
{ q\a[S*
this.sURL = sURL; o[o:A|n
this.nStartPos = nStart; 7N>oY$&)
this.nEndPos = nEnd; M{]e5+
nThreadID = id; 92!JKZe
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .2e1S{9
} #MUiL=
plK=D#)
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public void run() V/J>GRjw
{ O~.U:45t
while(nStartPos < nEndPos && !bStop) d4%dIR)
{ s0r"N7~
>[a FOA
fGb7=Fk
try{ I[ai:
URL url = new URL(sURL); mKV'jm0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1xz\=HOT
httpConnection.setRequestProperty("User-Agent","NetFox"); [_h%F,_ A
String sProperty = "bytes="+nStartPos+"-"; gF3TwAr
httpConnection.setRequestProperty("RANGE",sProperty); lY.B
Utility.log(sProperty); B]1HS`*7
x"vwWJNQ
Xq|nJ|h
InputStream input = httpConnection.getInputStream(); WM/#.
//logResponseHead(httpConnection); $'^&\U~?
YZibi
X6xx2v%D
byte[] b = new byte[1024]; [Gh"ojt]w
int nRead; opdu=i=E
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Qu`n&
{ rnu e(t
nStartPos += fileAccessI.write(b,0,nRead); k_!+V`Ro#
//if(nThreadID == 1) ~wTX>qV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X:Q$gO?[4
} hm3jpWi8
r=qLaPG
yIOLs}!SF
Utility.log("Thread " + nThreadID + " is over!"); qbXz7s*{
bDownOver = true; fE^uF[-7?
//nPos = fileAccessI.write (b,0,nRead); job[bhK'Jt
} $_)=8"Sn
catch(Exception e){e.printStackTrace ();} ,<sm,!^<r
} {DT4mG5
} eZNitGaU
DF'8GF&Rp
nX._EC
//打印回应的头信息 6yI}1g
public void logResponseHead(HttpURLConnection con) k,rWa
{ ;-Ss# &
for(int i=1;;i++) 1~'_K9eE
{ |q_ !. a
String header=con.getHeaderFieldKey(i); =2,0Wo]$
if(header!=null) W<NmsG})_g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,d|vP)SS
Utility.log(header+" : "+con.getHeaderField(header)); %,|ztH/ Q
else t^.'>RwW|
break; )Pli})
} M-Y0xWs
} &8sV o@Pa
k(vPg,X>m
Zm(dY*z5:J
public void splitterStop() &EovZ@u
{ Fd7*]a
bStop = true; H0a-(
} 9= V>f)R
'S?;J ,/
J{Tq%\a3
} Zhzy.u/>
,-'4L9
wVqd$nsY"
/* : ,p||_G&
**FileAccess.java bC~~5Cm
*//文件访问(定位，写) Q2/.6O8
package NetFox; ~Fw<eY
import java.io.*; ]TSg!H
m_*R.a
|y"jZT6R}t
public class FileAccessI implements Serializable{ 6z?gg3GV
~O: U|&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O"*`'D|hK
RandomAccessFile oSavedFile; ni6r{eSQ
long nPos; 2yKz-"E
z<pJYpxH
\cQ .|S
public FileAccessI() throws IOException R#(G%66
{ zoP%u,XL
this("",0); @Z;1 g
} =MLf[
XoR>H4xh
+y&d;0!
public FileAccessI(String sName,long nPos) throws IOException ?t rV72D
{ >qR~'$,$
oSavedFile = new RandomAccessFile(sName,"rw"); 9s`/~ a@
this.nPos = nPos; Bux'hc
oSavedFile.seek(nPos); ? _<[T
} W#XG;
*7" L]6
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public synchronized int write(byte[] b,int nStart,int nLen) }Qrab#v
{ WM,i:P)b
int n = -1; 4/*H.Fl
try{ ~p*1:ij
oSavedFile.write(b,nStart,nLen); b2kWjg.4
n = nLen; 0oU=RbC
} Lw*]EG|?
catch(IOException e) )%Ru#}1X6
{ a<m-V&4x
e.printStackTrace (); h qmSE'8
} ._CP% R
<7n]Ai@Y
1H{jy^sP7
return n; R$m`Z+/@
} iOqk*EL_r\
7Kf}O6nE
(~s|=Hxq|-
} f9TV%fG?
^#e~g/
Veji^-0E
/* rt4Z;
**SiteInfoBean.java O~@fXMthh
*/ 8Fq_i-u
package NetFox; >UHa
#S5`Pd!I
h`5)2n+P
public class SiteInfoBean { XU-m"_t
K:r\{#9
*t9eZ!_f?
private String sSiteURL; //Site's URL [!"XcFY:a
private String sFilePath; //Saved File's Path %<Q*Jf
private String sFileName; //Saved File's Name .px:e)iW
private int nSplitter; //Count of Splited Downloading File onte&Ed\
)`HA::
Vhg1/EgUr
public SiteInfoBean() mBk5+KyT
{//nSplitter的缺省值为5 ijUzC>O+q
//default value of nSplitter is 5 :&VcB$
this("","","",5); z4M1D9iPY
} ftZj}|R!
@Doyt{|T
.T.5TMiOSq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $.K?N@(W
{ Lz4ehWntO
sSiteURL= sURL; cd.brM
sFilePath = sPath; .%xzT J=!
sFileName = sName; %_gho
this.nSplitter = nSpiltter; |M5-5)
UAYd?r
rwqv V^
} /8gL.i$
"x*-PFT
,&]MOe4@>
public String getSSiteURL() '2^ Yw
{ w+AuMc
return sSiteURL; dpzw.Z
} ;IZ?19Q
g]$ 4~"|.
<{ru|-9
public void setSSiteURL(String value) K5"sj|d&
{ 3|kgTB-
sSiteURL = value; 'BqZOZw
} p1O6+hRio
kv?|'DN
-{g~TUz
public String getSFilePath() <GIwRVCU
{ raB+,Oi$G
return sFilePath; 0[a}n6XTk
} P-Su5F
2x}6\t
/c-nE3+rn
public void setSFilePath(String value) ,Og4 ?fS
{ _ PWj(});
sFilePath = value; ]/dVRkZeAE
} TKI$hc3|L
D`o<,Y
3y`F<&sA
public String getSFileName() .y4&rF$n
{ ?nFO:N<
return sFileName; "mIgs9l$
} BBL485`
pGWA\}'
N{joXHCu
public void setSFileName(String value) .;I29yk\XS
{ ;;&F1@3tBa
sFileName = value; y?z\L
} \0*l,i1&
XGs^rIf
&Cro2|KZhG
public int getNSplitter() zg}YGu|J
{ 1'KishHK=
return nSplitter; YUkud2,j
} ?y7w}W
3<(q }
>Hwc,j q
public void setNSplitter(int nCount) RA1yr+)
{ tIZ~^*'
nSplitter = nCount; zCe/Kukvy
} OkH\^
} grcbH
>SI<rR[~%
e>H:/24
/* TMj4w,g4
**Utility.java fEnQE EU~P
*/ nkY@_N
package NetFox; !,&yyx.
EESN\_{~.
dbF M,"^
public class Utility { :Ml7G
SN">gmY+
vA&Vu"}S
public Utility() ;5S}~+j
{ \C|cp|A*&
lpC @I^:
&=q! Wdw~
} _a -]?R
{BV4h%P]:
//线程睡眠 XB\zkf_}Xc
public static void sleep(int nSecond) 6Z! y
{ 'ZHdV,dd
try{ ;st\I
Thread.sleep(nSecond); u?0d[mC
} ]> G&jd7
catch(Exception e) igkz2SI
{ M7dU@Ag
e.printStackTrace (); i@$*Csj\9*
} LI W*4r!
} iS: #o>
P%>?[9!Nt
//日志 v,1F--v
public static void log(String sMsg) $|<m9CW
{ >S#ul?
System.err.println(sMsg); tFh|V pB
} I$jvXl=$
ijYvqZ_
.ER98
public static void log(int sMsg) N}Vn;29
{ shFc[A,r}
System.err.println(sMsg); b:MG@Hxc
} ]7/gJ>g,
} P]6}\ ]~
o$J6 ~dn
RUXCq`)"<
/* +x1/-J8_sg
**TestMethod.java La,QB3K/
*/ <y=ovkM3
package NetFox; PZOKrW
a(x?fa[D
v3^|"}\q5
public class TestMethod { 8Qrpa o
.iv3q?8.b
A WJWtUa
public TestMethod() {d!Y3+I%G
{ ///xx/weblogic60b2_win.exe IgX4.]W5
try{ At9X]t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K0fv( !r{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;VzMU ;j
SiteFileFetch fileFetch = new SiteFileFetch(bean); =>LZm+P
fileFetch.start(); %+tV/7|F
} &RY)o^g[4
catch(Exception e){e.printStackTrace ();} b|?;h21rG
optBA3@e!
z+VV}:Q
} G[yI*/E;
Zf:]Gq1
>Y&KTSD"
public static void main(String[] args) vjlGXT`m
{ =*MR(b>
new TestMethod(); b X,Siz:F
} l)|lTOjb
} >&K!VQ{g
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