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)); -b+VzVJZ
} qeLfO
for(int i=0;i<nEndPos.length-1;i++) x!GHUz*:uz
{ X@KF}x's
nEndPos = nStartPos[i+1]; "Mzb
} h<2o5c|
nEndPos[nEndPos.length-1] = nFileLength; x`K<z J
} "&*O7cs$pA
} 8o43J;mA
AE!DftI
h^R EBPe
//启动子线程 zu}oeAQc$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s<VNW
for(int i=0;i<nStartPos.length;i++) @NlE2s6a
{ +-YMW;5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7/QQ&7+NkS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9I>qD
nStartPos,nEndPos,i); gSQq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6Mu_9UAl`
fileSplitterFetch.start(); 1'DD9d{qN
} sFv68Ag+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z18T<e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); nNJU@<|{*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?g gl8bzA
nEndPos = " + nFileLength); |?k3I/;
// fileSplitterFetch[nPos.length-1].start(); rOd<nP^`\
^=:e9i3u
o?(({HH
//等待子线程结束 x01n
//int count = 0; (os}s8cIh
//是否结束while循环 !h3$C\
boolean breakWhile = false; d-Vttxa6
c,nE@~ul2
I3`WY-uv
while(!bStop) 5%,5Xe4p
{ Hhx"47:
write_nPos(); 3V~871:-~
Utility.sleep(500); wSoIU,I
breakWhile = true; ssaEAm:
Ji4xor
pw|f4c7AH
for(int i=0;i<nStartPos.length;i++) B1)gudP`
{ J%ng8v5ex
if(!fileSplitterFetch.bDownOver) 4po zTe
{ y%%D="
breakWhile = false; |Iei!jm
break; x=>B 6o-f
} 2F*spu
} d-/{@
if(breakWhile) 3cfJ(%'X
break; "(bnr0
YaiogA
u^.7zL+
//count++; MLwh&I9)
//if(count>4) i) v ]
// siteStop(); {8+FxmH
} ROcI.tL
8R?X$=$]!.
"Bl]_YPv
System.err.println("文件下载结束！"); ;e,_F/@`
} x(oL\I_Z
catch(Exception e){e.printStackTrace ();} to9~l"n.s
} }j<:hDQP
y4sKe:@2
}-YM>q
//获得文件长度 4WCWu}
public long getFileSize() dH:z_$Mg
{ 7<FI[
int nFileLength = -1; [7x,&
try{ #dyz
URL url = new URL(siteInfoBean.getSSiteURL()); o/0cd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "#zSk=52z
httpConnection.setRequestProperty("User-Agent","NetFox"); We%HdTKT
qTc-Z5
9C&Xs nk
int responseCode=httpConnection.getResponseCode(); <Y%km[Mh
if(responseCode>=400) 38ac~1HjE
{ Gy}WZ9{
processErrorCode(responseCode); dy/\>hu
return -2; //-2 represent access is error 5cahbx1"
} r'bctFsD
Xwz9E!m
F}9!k LR
String sHeader; xvo""R/g8
pJ8;7u
K1y]
for(int i=1;;i++) E"i<fr T
{ `)5,!QPQ7u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a,eR'L<"*-
//Utility.log(in.readLine()); 'T=$Q%Qv
sHeader=httpConnection.getHeaderFieldKey(i); akR+QZ,)
if(sHeader!=null) ])`+ 78
{ q!UN<+k\h
if(sHeader.equals("Content-Length")) 0,a/t jSr
{ 25EuVj`zL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +yC]f b
break; X}jWNN
} MU_8bK9m
} i'XW)n
else N RB>X
break; E2.@zY|:
} HJ5 Ktt
} KDTG9KC
catch(IOException e){e.printStackTrace ();} * AsILK0
catch(Exception e){e.printStackTrace ();} ^YVd^<cE
'v|R' wi\
jLc"1+
Utility.log(nFileLength); &Bn> YFu
Mw{0A\6
p7SX,kpt>
return nFileLength; kT7x !7C
} <HYK9{Q
Cn\5Vyrl
h>0R!Rl8
//保存下载信息（文件指针位置） op!ft/Yyb
private void write_nPos() :vsBobiJ
{ F7o#KN*.]
try{ 1#nR$
output = new DataOutputStream(new FileOutputStream(tmpFile)); cXcrb4IKD
output.writeInt(nStartPos.length); pTzwyj!SD
for(int i=0;i<nStartPos.length;i++) [K5#4k
{ TNi4H:\
// output.writeLong(nPos); MxXf.iX&
output.writeLong(fileSplitterFetch.nStartPos); +V2\hq[{
output.writeLong(fileSplitterFetch.nEndPos); %P3|#0yg0
} #.Q3}[M
output.close(); 9^yf'9S1
} |ZJ<J)y
catch(IOException e){e.printStackTrace ();} D./!/>@f
catch(Exception e){e.printStackTrace ();} rN$U%\.I
} *U<l$gajq
$!?tJ@{
Kp]\r-5UD>
//读取保存的下载信息（文件指针位置） z2.9l?"rfQ
private void read_nPos() l g0 'qH8
{ 30BFwNE
try{ XIep3l*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eT!*_.' e
int nCount = input.readInt(); -'!K("
nStartPos = new long[nCount]; $m hIXA.
nEndPos = new long[nCount]; AqqD!
for(int i=0;i<nStartPos.length;i++) st7\k]J\
{ MC'2;,
nStartPos = input.readLong(); (ncm]W
nEndPos = input.readLong(); jH5VrN*Q
} ^<$$h
input.close(); s(2/]f$
} 4z;@1nN_8a
catch(IOException e){e.printStackTrace ();} ,0pCc<
catch(Exception e){e.printStackTrace ();} }q$6^y
} OuZPgN
{fd/:B 7T
Z91{*?
private void processErrorCode(int nErrorCode) L- '{
{ k vuSE
System.err.println("Error Code : " + nErrorCode); pqT+lai)#
} ]3KMFV}
hRU5CH/!
v47S9Vm+
//停止文件下载 CjQ)Bu*4
public void siteStop() "e-RV
{ "VIoVu
bStop = true; KfPYH\0
for(int i=0;i<nStartPos.length;i++) `F(ghC
fileSplitterFetch.splitterStop(); tz^2?wO
',_E;(
w=;Jj7}L
} }CM</
} }EMds3<
//负责部分文件的抓取 R(^2+mV?
**FileSplitterFetch.java 7A,lQh
*/ xs}3=&c(
package NetFox; _o+z#Fnz
M+|J;caX
DN X-\
import java.io.*; 7Rq|N$y.3
import java.net.*; 5LX'fL7zU
#^>Md59N
15l{gbCW
public class FileSplitterFetch extends Thread { IG(1h+5R(
pzcl@
kq4ii`zi8
String sURL; //File URL ! ^ DQX=1
long nStartPos; //File Snippet Start Position id?B<OM
long nEndPos; //File Snippet End Position h>a/3a$g
int nThreadID; //Thread's ID ~+)sL1lx
boolean bDownOver = false; //Downing is over + g*s%^(E
boolean bStop = false; //Stop identical <Pnz$nH:e
FileAccessI fileAccessI = null; //File Access interface Sb|9U8h
>WZ_) `R
6OPYq*|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,_iR
{ >^Z==1
this.sURL = sURL; F,.dC&B
this.nStartPos = nStart; AZ7m=Q97
this.nEndPos = nEnd; ~u.((GM
nThreadID = id; +7V4mF!u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }o:sU^Pwa
} }\?]uNH
2R`dyg
?= RC?K
public void run() 2mt S\bAF
{ {/2 _"H3:
while(nStartPos < nEndPos && !bStop) |=rb#z&
{ 3;'RF#VL
*dpKo&y
xm*6I
try{ 05ZF>`g*
URL url = new URL(sURL); 8WP|cF]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pIhy3@bY
httpConnection.setRequestProperty("User-Agent","NetFox"); Hs#q 7
String sProperty = "bytes="+nStartPos+"-"; W1\F-:4L@
httpConnection.setRequestProperty("RANGE",sProperty); Ve9*>6i&-4
Utility.log(sProperty); \s@7pM=(
84f~.45
0_f6Qrcj
InputStream input = httpConnection.getInputStream(); N3m~nEj
//logResponseHead(httpConnection); "Nh}_jO
)KbzgmLr
K^Ixu~
byte[] b = new byte[1024]; 50R&;+b
int nRead; O?OG`{k
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U?e.)G
{ 2'-!9!C
nStartPos += fileAccessI.write(b,0,nRead); sKniqWi
//if(nThreadID == 1) sMDHg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }1BpIqee
} d8Sr,t+
]b&O#D9
#HyE-|_C
Utility.log("Thread " + nThreadID + " is over!"); M@a=|N~
bDownOver = true; x&d:V
//nPos = fileAccessI.write (b,0,nRead); &fRZaq'2R
} =8W'4MC
catch(Exception e){e.printStackTrace ();} :(TOtrK@
} =C4!h'hz
} p->b Vt
+'ADN!(B_
\2OjIEQQ
//打印回应的头信息 P>wTp)
public void logResponseHead(HttpURLConnection con) *V[6ta'
{ *R_mvJlT
for(int i=1;;i++) ,1ceNF#oL
{ @E !`:/k
String header=con.getHeaderFieldKey(i); Hq!|(
if(header!=null) j1i<.,0g
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;0JK>c ]#
Utility.log(header+" : "+con.getHeaderField(header)); e"^n^_9
else `&/~%>
break; Z9p`78kYyh
} *Hed^[sO
} ( SiwO.TZ
4<<T#oW.:G
_J ZlXY
public void splitterStop() p;P cD
{ }~+_|
bStop = true; 7T/hmVi_
} +2Wijrn
)9~-^V0A^>
%"=qdBuk
} vE$n0bL2
>pj)va[Q
<F&53N&Zc
/* R.)w l
**FileAccess.java met`f0jw
*//文件访问(定位，写) Y<)9TU:D!
package NetFox; rZkl0Y;n\
import java.io.*; 5hg ^K^ZZ
+WfO2V.
-esq]c%3
public class FileAccessI implements Serializable{ Y8@TY?
gK",D^6T*Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f@aFs]xV
RandomAccessFile oSavedFile; h$_5)d~
long nPos; oBI@.&tG}
GSaU:A
~(Xzm
public FileAccessI() throws IOException Jknit
{ bc%N !d
this("",0); c?7Wjy
} 2/f!{lz](
HE.YfD)
TBu[3X%
public FileAccessI(String sName,long nPos) throws IOException z8*{i]j
{ 4u+4LB*
oSavedFile = new RandomAccessFile(sName,"rw"); D\ kd6
this.nPos = nPos; 2y#[uSqB
oSavedFile.seek(nPos); M0Vs9K=
} h:~ 8WV|
Q/y"W,H#
]v|n'D-?
public synchronized int write(byte[] b,int nStart,int nLen) V4tObZP3Ff
{ AB[#
int n = -1; K/IG6s;Xj
try{ zPW_
oSavedFile.write(b,nStart,nLen); QvvH/u
n = nLen; V)#rP?Y
} g;._Q
catch(IOException e) C~q&
{ 9Pjw<xt
e.printStackTrace (); |N%#;7
} 1qN+AT
W_Eur,/`
w+G+&ak<
return n; &+Yoob]P
} ie4BE'
u[+/WFH
U "kD)\
} 'l&bg8K9
/;9iDjG
P`]p&:
/* VB&`g<
**SiteInfoBean.java 0o_wy1O1,
*/ -_+,HyJP
package NetFox; O]%Vh l
j5~nLo2
R~!md
public class SiteInfoBean { NjP7?nXSx
\Rz-*zr&
y6`zdB
private String sSiteURL; //Site's URL Z?j4WJy-[
private String sFilePath; //Saved File's Path 2YhtD A
private String sFileName; //Saved File's Name `Yw:<w\4C
private int nSplitter; //Count of Splited Downloading File KreF\M%Ke
5sI9GC
#{x4s?
public SiteInfoBean() pL pBP+i
{//nSplitter的缺省值为5 I`4k5KB;
//default value of nSplitter is 5 m'YYkq(5%Z
this("","","",5); B0dv_'L}L
} X(dHhO
6 TSC7jO
+_v#V9?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mz?1J4rt
{ Fa-F`U@h(m
sSiteURL= sURL; rUWC=?Q
sFilePath = sPath; ^<w3i?KPW
sFileName = sName; {1m.d;(1
this.nSplitter = nSpiltter; >NjgLJh
3w$Ib}7
5KRI}f
} H`EsFKw\%
hYY-Eq4TC
U8GvUysB!
public String getSSiteURL() !7y:|k,ac
{ k\A[p\
return sSiteURL; M$MFUGS'
} [&K"OQ^\2h
N={0A
ZP;WXB`
public void setSSiteURL(String value) t^SND{[WcM
{ gQ=l\/H
sSiteURL = value; `~+[pY1r
} YT\.${N
r"W,G/;h
^zVW 3Y q
public String getSFilePath() #xfPobQ>il
{ &l _NCo2
return sFilePath; dA=T+u
} t:yJ~En]=
9KDm<Q-mf
YW'l),Z
public void setSFilePath(String value) {LoNp0i1a
{ *4?%Y8;bF6
sFilePath = value; 5%;=(Oig
} N5|wBm>m
\>p\~[cxt
*@zya9y9q
public String getSFileName() zIy&gOX
{ Xn*>qm
return sFileName; 8Y&_X0T|
} se`^g ,]P
ql(~3/kA_
)bR`uV9<
public void setSFileName(String value) [6cf$FS9
{ )A=&3Ui)ab
sFileName = value; M:d} P
} =v49[i
MKZq*
>o|.0aw<
public int getNSplitter() B> V)6\
{ w*krPaT3
return nSplitter; N`rz>6,k1
} 6<{XwmM
7 jiy9[
*(CV OY~
public void setNSplitter(int nCount) $[{YE[a
{ EVW\Z 2N.
nSplitter = nCount; 2b^E8+r9
} ">x"BP
} JE ''Th}
E4qQ
b3l~wp6>
/* #?klVK&e/
**Utility.java yLEAbd%+
*/ -AZ\u\xCB
package NetFox; R-OQ(]<*
7p[NuU*Gg
(%SKTM
public class Utility { %%qg<iO_
Da&Brm
2"8qtG`Et
public Utility() ` 3h,Cy^
{ |ohCA&k%;
v9XevLs
=} flmUv~
} E?cf#;2h8m
]3I@5}5%
//线程睡眠 m)e~HP7M
public static void sleep(int nSecond) DQ9}('^
{ z(Q 5?+P
try{ IA^*?,AZy
Thread.sleep(nSecond); ]@ N::!m
} $n_ax\15
catch(Exception e) AGK{t+`
{ dr^MW?{a\
e.printStackTrace (); 2*TPW
} nZ8jBCh
} ]7J*(,sp
/A1qTG=Br
//日志 cd]def[d
public static void log(String sMsg) A&L2&ofV&q
{ Wh^wKF~%
System.err.println(sMsg); X{tfF!+iy
} rL|9Xru
.9@y*_9
g![?P"i^t
public static void log(int sMsg) Hl=M{)q@
{ p61F@=EL
System.err.println(sMsg); @f`s%o
} iG+=whvL
} H/$oGhvl
'.IR|~Y
ASULg{
/* V~]&1
**TestMethod.java ^EcwY- Qr
*/ ; ~#uH7k
package NetFox; k`NXYf:
g [c^7
{"mb)zr
public class TestMethod { >N-l2?rE
".sRi
kS<9cy[O
public TestMethod() nJcY>Rp?
{ ///xx/weblogic60b2_win.exe QS%t:,0lp
try{ z@U5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DTz)qHd#X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i^}ib RQbN
SiteFileFetch fileFetch = new SiteFileFetch(bean); g96]>]A<{
fileFetch.start(); F&$~]R=&
} /TY=ig1z
catch(Exception e){e.printStackTrace ();} xbD]EC
g]jCR*]
g<^-[w4/
} ->`R[k
];*?`}#
!XQ)>T^G5
public static void main(String[] args) *&tv(+P
{ T4h&ly5 f
new TestMethod(); oD=+
} lD6PKZ\RIj
} mO&zE;/[
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