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)); N'-[>w7vK2
} U$<" .q
for(int i=0;i<nEndPos.length-1;i++) 89;@#9
{ 6Ol9P56j
nEndPos = nStartPos[i+1]; H9PnJr8 \
} 0:>hK\F#
nEndPos[nEndPos.length-1] = nFileLength; X:I2wJDs\
} jr_z ?
} hF$qH^-c*A
<hj2'dU
~%C F3?e6
//启动子线程 [0hahR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Lr5{c5M
for(int i=0;i<nStartPos.length;i++) 01n132k
{ y4LUC;[n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ggiy{CdR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <9piKtb|L
nStartPos,nEndPos,i); lSW'qgh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IM7<z,*oF
fileSplitterFetch.start(); z#ki# o
} ]@ke_' "
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i;U*Y *f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "M!m-]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6 Bdxdx*zt
nEndPos = " + nFileLength); UAT\ .
// fileSplitterFetch[nPos.length-1].start(); 9cUa@;*1
1YJ?Y
biU_ImJ>0
//等待子线程结束 |/^S%t6*
//int count = 0; gBi3^GxjM?
//是否结束while循环 3l45(%g+
boolean breakWhile = false; (XW'1@b
E5@=LS
y`j=(|DV
while(!bStop) (tOhuSW
{ G_J}^B*?%v
write_nPos(); \~z$'3H`
Utility.sleep(500); LiV&47e*>
breakWhile = true; Hz."4nhv
~59lkr8
:i4(cap&}F
for(int i=0;i<nStartPos.length;i++) -{ 1P`&G
{ IsE3-X|
if(!fileSplitterFetch.bDownOver) kY'Wf`y(
{ Ie!&FQe2q
breakWhile = false; e\cyiW0
break; Mmu#hb|W
} H$C*&p
} BZHoRd{EH
if(breakWhile) ]W14'Z
break; i9XpP(mf
Q,^/Lm|]k
kx?Yin8K
//count++; MO0NNVVi%U
//if(count>4) `D |/g;
// siteStop(); 77yYdil^W+
} b<~-s sL7a
bTmhz
8K?}!$fz
System.err.println("文件下载结束！"); ThgJ '
} G^#>HE|
catch(Exception e){e.printStackTrace ();} W h9L!5
} ;"x+V gS'
GT6i9*tb#
fc8ODk*;E
//获得文件长度 k|?[EWIi^
public long getFileSize() ?L7DVwVa,I
{ 2=n`z)R
int nFileLength = -1; 1xd6p
try{ T+@i;M
URL url = new URL(siteInfoBean.getSSiteURL()); Yq6 @R|u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 69)"T{7
httpConnection.setRequestProperty("User-Agent","NetFox"); &Wcz~Gx3Q
Se'SDJl=
4n6AK`E
int responseCode=httpConnection.getResponseCode(); Lr"cO|F
if(responseCode>=400) Ht(TYq
{ 5rB>)p05[
processErrorCode(responseCode); 4RB%r
return -2; //-2 represent access is error gM>?w{!LBx
} '~K]=JP
{qi#
_7Y-gy#\a
String sHeader; P@ew' JL%
8`urkEI^r
ub-e!{
for(int i=1;;i++) D^6iQW+.P
{ g/!MEOVx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V~j^
//Utility.log(in.readLine()); OxGfLeP.R!
sHeader=httpConnection.getHeaderFieldKey(i); >fI\f <ez
if(sHeader!=null) UWC4PWL,>C
{ >_ZEQC
if(sHeader.equals("Content-Length")) p03I&d@w>
{ SDO:Gma
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |~ fI=1;;x
break; (9I(e^@]
} F+(S-Qk1
} [BD`h
else ZAn @NA=
break; jDb\4QyC
} 7WS$fUBi
} (KyOo,a
catch(IOException e){e.printStackTrace ();} re[5lFQ~Z
catch(Exception e){e.printStackTrace ();} wrgB =o
2}pZyS
^rO"U[To
Utility.log(nFileLength); 1bQO:n):~
=EFh*sp
_MTZuhY
return nFileLength; L7buY(F(
} \]f+{d-&
j AOy3c
{:!>Y1w>
//保存下载信息（文件指针位置） TU^ZvAO&
private void write_nPos() l1k&@1"
{ tUxH6IS
try{ \XV8t|*
output = new DataOutputStream(new FileOutputStream(tmpFile)); /Q(boY{
output.writeInt(nStartPos.length); %AA&n*m
for(int i=0;i<nStartPos.length;i++) ]b%U9hmL^f
{ ZN$%\,<
// output.writeLong(nPos); l$\2|D
output.writeLong(fileSplitterFetch.nStartPos); v:4j3J$z
output.writeLong(fileSplitterFetch.nEndPos); ; >H1A
} d-1D:Hs?
output.close(); Z3{1`"\<K
} NT5=%X]
catch(IOException e){e.printStackTrace ();} I*.nwV<
catch(Exception e){e.printStackTrace ();} :Q("
} F*@2)
iKrk?B<
uM1$3<
//读取保存的下载信息（文件指针位置） #W)m({}
private void read_nPos() /-FV1G,h
{ |Qcz5M90e
try{ 9&f+I@K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T,9q~*"
int nCount = input.readInt(); S!u8JG1
nStartPos = new long[nCount]; PY7H0\S)
nEndPos = new long[nCount]; \f^xlX3&`
for(int i=0;i<nStartPos.length;i++) ca7Y+9< ;
{ &mVClq
nStartPos = input.readLong(); e`g+Jf`AT
nEndPos = input.readLong(); y@~ VE5N
} MZQDFuvDxZ
input.close(); W.[!Q`
} W..*!UGl
catch(IOException e){e.printStackTrace ();} <A Hzs
catch(Exception e){e.printStackTrace ();} R;Dj70g
} v(yJGEf0
C @<T(`o
r'{N_|:vv
private void processErrorCode(int nErrorCode) G$TO'Ciu:
{ MF<ZB_@
System.err.println("Error Code : " + nErrorCode); ]?1_.Wjtt
} ^PNDxtd|v
,3_Sf?
fV>d_6Lf}
//停止文件下载 oMg-.!6
public void siteStop() Gl'G;F$Y-
{ N`efLOMl]
bStop = true; @!dIa1Q"
for(int i=0;i<nStartPos.length;i++) d"Zu10
fileSplitterFetch.splitterStop(); 1qNO$M
N gF7$@S
tE=09J%z
} 2)\->$Q(H
} [nig^8
//负责部分文件的抓取 ?}8r h%
**FileSplitterFetch.java Jg=!GU/::
*/ VrPsy) J68
package NetFox; p*0[:/4
/Z?o%/bw:
_?O'A"
import java.io.*; LJ <pE;`d
import java.net.*; 7d%x7!E
,uC-^T |n
u@e.5_:S)
public class FileSplitterFetch extends Thread { 1}la)lC
k^;n$r"i5
wO%lM
String sURL; //File URL s$pXn&:
long nStartPos; //File Snippet Start Position 8&8!(\xv
long nEndPos; //File Snippet End Position <9X@\uvU.<
int nThreadID; //Thread's ID yR|2><A
boolean bDownOver = false; //Downing is over uFSU|SDd.
boolean bStop = false; //Stop identical M]6+s`?r
FileAccessI fileAccessI = null; //File Access interface \78^ O
_x(hlHFk
082iEG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bC:sd2s
{ RKzty=j4
this.sURL = sURL; [pTdeg;QE
this.nStartPos = nStart; k)7i^1U
this.nEndPos = nEnd; 7oF3^K'S
nThreadID = id; rmA?Xlh\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d*{Cv2A.
} l,h`YIy
W>a}g[Ad
}~zDcj_
public void run() )/'WboL
{ td7(444]
while(nStartPos < nEndPos && !bStop) %z@ Z^Jv
{ b3-j2`#
+7w5m
m0;j1-t
try{ Lp:VU-S
URL url = new URL(sURL); 8WQ#)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #[9UCX^=
httpConnection.setRequestProperty("User-Agent","NetFox"); lfDd%.:q4S
String sProperty = "bytes="+nStartPos+"-"; :a/rwZ[r
httpConnection.setRequestProperty("RANGE",sProperty); 13F]7l-#
Utility.log(sProperty); @Nsn0-B?ne
(n7xYGfYS
^ 34Ng
InputStream input = httpConnection.getInputStream(); *:TwO=)
//logResponseHead(httpConnection); `ZEFH7P
;]1t|td8
B,%6sa~I
byte[] b = new byte[1024]; }nPt[77U_7
int nRead; *$%~/Q@]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *d=}HO/
{ $,by!w'e:l
nStartPos += fileAccessI.write(b,0,nRead); D%o(HS\E
//if(nThreadID == 1) Vv+nq_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7<]&pSt=
} %OgK{h
i kfJ!f
W8^A{l4
Utility.log("Thread " + nThreadID + " is over!"); &T,,fz$
bDownOver = true; I1>f2/$z*
//nPos = fileAccessI.write (b,0,nRead); G 0pq'7B
} H(.9tuA
catch(Exception e){e.printStackTrace ();} udUc&pX
} |MGT8C&^!
} #1$4<o#M
M5:.\0_
3Ed
//打印回应的头信息 eGQ4aQhi
public void logResponseHead(HttpURLConnection con) (LTu=1
{ r~T!$Tb
for(int i=1;;i++) 1(Vv-bq$
{ Uzvd*>mv
String header=con.getHeaderFieldKey(i); YQ:$m5ai
if(header!=null) j;}-x1R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s:6K'*
Utility.log(header+" : "+con.getHeaderField(header)); jGo%Aase
else ! N2uJ?t
break; ^}$t(t
} >4wigc
} i/_rz.c~3
f91]0B`C
>mA]2gV<a
public void splitterStop() Y<W9LF
{ Bv~^keuj3t
bStop = true; ,X_3#!y
} Te}gmt+#%
16Ka>=G
Fu{VO~w
} geK;r0(f
!%R):^R8
-'miM ~kG[
/* %_:L_VD@
**FileAccess.java 19GF%+L ,
*//文件访问(定位，写) <$?#P#A
package NetFox; sT1OAK\^
import java.io.*; U3Gg:onuE
.CEC g*f
-<x%
public class FileAccessI implements Serializable{ fsOlg9
PtuRXx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 BDfMFH[1
RandomAccessFile oSavedFile; X_X7fRC0
long nPos; /'{vDxZf R
<fBJ@>
tBzE(vW
public FileAccessI() throws IOException [K #$W
{ XO?WxL9k]
this("",0); L>/$l(
} SPb`Q"
g~21|Sa$[
/xgC`]-
public FileAccessI(String sName,long nPos) throws IOException y'>9'/&
{ OcF_x/#
oSavedFile = new RandomAccessFile(sName,"rw"); bl!pKOY
this.nPos = nPos; l5^Q
oSavedFile.seek(nPos); Yl au
} W<&/5s
5KB Z-,
|+8rYIms`
public synchronized int write(byte[] b,int nStart,int nLen) V8F!o
{ Oq<3&*
int n = -1; !8|r$mN8
try{ v,Kum<oi?
oSavedFile.write(b,nStart,nLen); MbYgGE,LA
n = nLen; 8?L-3/
} W="pu5q$5
catch(IOException e) rJf{YUZe
{ a++gwl
e.printStackTrace (); @)Vb?|3
} nO6UlY
2va[= >_
p?Ux1S
return n; ]{i0?c
} =zAFsRoD_B
?8grK
ecl6>PS$'
} )$Ib6tYY
]Y$Wv9S6
nO`[C=|
/* ^WWr8-
**SiteInfoBean.java &/' O?HWl
*/ >9nVR
package NetFox; of7'?]w
&Pv$nMB$I
|a[" ^ 2
public class SiteInfoBean { A-vYy1,'
K;THYMp/[
s0_HMP x
private String sSiteURL; //Site's URL W1o6Sh8v(
private String sFilePath; //Saved File's Path KpG'E
private String sFileName; //Saved File's Name cJm},
private int nSplitter; //Count of Splited Downloading File (`Y;U(n
!2B~.!&
A][ ;v
public SiteInfoBean() 'Eia=@
{//nSplitter的缺省值为5 Z{ YuX
//default value of nSplitter is 5 56c3tgVF
this("","","",5); ]E:L
} jbg9EtQ!*
6U|"d[
@ajdO/?(Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b-`P-
{ XOS^&;
sSiteURL= sURL; Vd.XZ*}r*
sFilePath = sPath; 7Fa<m]k
sFileName = sName; GdScYAC
this.nSplitter = nSpiltter; "7(@I^'t6
0:`YY8j1k
es69P)
} "E5=AWd
'Q7t5v@FF
jfvlkE-uK
public String getSSiteURL() |d42?7}
{ Kzt:rhiB
return sSiteURL; rmX5-k
} [=-,i#4
o2YHT \P n
kotKKs
public void setSSiteURL(String value) <#Fex'4
{ jtpk5 fJB
sSiteURL = value; ept:<!4
} {9@E[bWp#
DB jUHirK
\Ff]}4
public String getSFilePath() ]=|iO~WN
{ `N7erM
return sFilePath; &8%^o9sH
} Iw$T'I+4W
w3fD6$
Uq%|v
public void setSFilePath(String value) "$"<AKCwS
{ rTC|8e
sFilePath = value; P4MP`A
} 6QPbmO]z
w3>G3=b
f4X}F|!h
public String getSFileName() ?q'r9Ehe
{ Xn!=/<TIVz
return sFileName; &$qIJvMiK
} ]/R>nT
]YDqmIW
"tK3h3/Xv
public void setSFileName(String value) )B@&q.2B=
{ N0 t26| A
sFileName = value; (hY^E(D
} Jju?v2y`
SN QLEe
l29AC}^
public int getNSplitter() ]?jmRk^.
{ Gv(n2r
return nSplitter; T(qHi?Y
} (ke<^sv7!
b]8\%=d
I= z+`o8
public void setNSplitter(int nCount) .lcgM
{ ,*p(q/kJh~
nSplitter = nCount; !<-+}X+o8$
} x||b:2
} lnxA/[`a
Oo\~'I
@zix%x
/* 5kv]k?
**Utility.java [9p@uRE
*/ n;dWb$:
package NetFox; 52 DSKL
.B$3y#TOb
}4>#s$.2
public class Utility { k"FY &;G(G
|@ZyD$?
RQn3y-N]
public Utility() y+VRD
{ g{7?#.7
3'`X_C|d53
`,wX&@sN
} l%xeM!}
klj.\wg/p{
//线程睡眠 T~N877
public static void sleep(int nSecond) t2%gS" [
{ kZ 9n@($B
try{ SR\$fmo
Thread.sleep(nSecond); k1WyV_3
} ]0p*EB=C*
catch(Exception e) 23UXOY0BW
{ vf_pEkx*wD
e.printStackTrace (); @]{:juD~
} l_=kW!l
} <gr2k8m6$
m9m~2
//日志 z;i4F.p
public static void log(String sMsg) iwEHEi%
{ YpbJoHiSH
System.err.println(sMsg); `JG7Pl/ih
} yz=6 V%
]GHx<5Q:\
i0&]Ig|;
public static void log(int sMsg) $2*&\/;-E!
{ SB!m&;Tb
System.err.println(sMsg); o&:n>:im
} %PU{h
} qv+}|+aL:
SVyJUd_
=}4lx^`oeT
/* l'Z `%}R
**TestMethod.java mc5$-}1V,
*/ `?Xt ,
package NetFox; kC6s_k
qfEB VS(
N6-bUM6%I
public class TestMethod { GEf[k OQ
04<T2)QgK
D61e
public TestMethod() z0&I>PG^
{ ///xx/weblogic60b2_win.exe }\\6"90g*
try{ T]J#>LBd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Bcy$"F|r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &28n1
SiteFileFetch fileFetch = new SiteFileFetch(bean); Sst`*PX:
fileFetch.start(); l{x?i00tAS
} m4@w M?
catch(Exception e){e.printStackTrace ();} &($Zs'X
32V,25 (`5
FwGMrJW
} j2|!h%{nI
lf9_!`DGV
*C?x\.\C
public static void main(String[] args) V.274e
{ Pi|oO-M
new TestMethod(); =!Y{Mz
} 84dej<
} u~d&<_Z
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