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)); )5U7w
} ; JHf0
for(int i=0;i<nEndPos.length-1;i++) *_uGzGB&G
{ `$VnB
nEndPos = nStartPos[i+1]; kPp7;U2A
} 6)3pnhG9
nEndPos[nEndPos.length-1] = nFileLength; |=Pw-uk
} ^+dL7g?+
} eG5xJA^
KlRIJOS
eKqo6P:#f
//启动子线程 O/f+B}W
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; qP[jtRIN
for(int i=0;i<nStartPos.length;i++) L8KMMYh[
{ (Mt-2+"+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f@xjNm*'Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &m@DK>
nStartPos,nEndPos,i); v}"DW?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~w$ ^`e!]
fileSplitterFetch.start(); LZ~}*}jy
} @yn1#E,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I6 Q{ Axy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :W1B"T<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4"%LgV`
nEndPos = " + nFileLength); )>^!X$`3
// fileSplitterFetch[nPos.length-1].start(); sMWNzt
y)+lU
h!]=)7x;
//等待子线程结束 NB)22 %
//int count = 0; yUFT9bD
//是否结束while循环 ,S=ur%
boolean breakWhile = false; Md1ePp]
oei2$uu
#;>v,Jo
while(!bStop) ]KRw[}z
{ 2xpI|+a%
write_nPos(); |VML.u:N
Utility.sleep(500); n]P,5
breakWhile = true; w:[\G%yQ
FO xZkU\e=
l>jNBxB|/A
for(int i=0;i<nStartPos.length;i++) 4Y}{?]>pu
{ Z[zRZ2'i5
if(!fileSplitterFetch.bDownOver) >iI-Cs7TD
{ .d%CD`8!
breakWhile = false; @7,k0H9Moa
break; rW0-XLbL5H
} |jTRIMj%,_
} : ]~G9]R`
if(breakWhile) ~myY-nEY
break; xEqr3(
R"qxT.P(
`"qSr%|
//count++; XlU`jv+
//if(count>4) W v!%'IB
// siteStop(); ]*vv=@"`e
} 4xD`Z_U
:5BVVa0oR
QNgfvy
System.err.println("文件下载结束！"); 4Yya+[RY
} }:hN}*H
catch(Exception e){e.printStackTrace ();} /}$D&KwYg
} 7y'2
aqN6.t
J`d;I#R%c
//获得文件长度 ._US8
public long getFileSize() +I r
{ C7T}:V](q
int nFileLength = -1; F'9#dR?
try{ FWDAG$K@0
URL url = new URL(siteInfoBean.getSSiteURL()); C{U"Nsu+1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'o]8UD(
httpConnection.setRequestProperty("User-Agent","NetFox"); zP|^) h5
Y4I;-&d's
pt=H?{06
int responseCode=httpConnection.getResponseCode(); ]}0QrD
if(responseCode>=400) &Z6s\r%
{ *VgiJ
processErrorCode(responseCode); C0%yGLh&
return -2; //-2 represent access is error SK;c D>)
} o==:e
3DS&-rN
Iju9#b6
String sHeader; F!&$Z .
:"I!$_E'
yJ?S7+b
for(int i=1;;i++) q=`i
{ Dt=@OZW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0 pPSg9
//Utility.log(in.readLine()); :2(U3~3:
sHeader=httpConnection.getHeaderFieldKey(i); 8zzY;3^h;
if(sHeader!=null) `(o:;<&3
{ -]kvM
if(sHeader.equals("Content-Length")) ;HoBLxb P
{ .l$:0a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h0)Dj(C
break; k}FmdaPI'
} I::|d,bR!
} |!E: [UH
else JBt2R=
break; H[D<G9:
} F;sZc,Y,^
} 1j?+rs+o-
catch(IOException e){e.printStackTrace ();} .6[7D
catch(Exception e){e.printStackTrace ();} /l1OC(hm
VHqHG`}:
/Xk-xg+U
Utility.log(nFileLength); 25{-GaB
+Fa!<txn
^c|_%/
return nFileLength; &r)[6a$fW
} 1V:I}~\
iqr/MB,W
v,^W& W.
//保存下载信息（文件指针位置） Z|$M 9E
private void write_nPos() x ?24oO
{ 1U6z2i+y
try{ &hu>yH>j
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~kFL[Asnaf
output.writeInt(nStartPos.length); !\5w<*p8
for(int i=0;i<nStartPos.length;i++) liU8OXBl
{ ]I'dnd3e
// output.writeLong(nPos); O QGKH6q
output.writeLong(fileSplitterFetch.nStartPos); y,s`[=CT
output.writeLong(fileSplitterFetch.nEndPos); h yK&)y?~
} i8->3uB
output.close(); ,9Si3vn
} D1R$s*{
catch(IOException e){e.printStackTrace ();} _9:r4|S
catch(Exception e){e.printStackTrace ();} 2mEvoWnJ
} a&RH_LjM
I>JBGR`j
MUn(ZnQy|
//读取保存的下载信息（文件指针位置） |ya.c\}q
private void read_nPos() ohna1a^
{ qsWy <yL+
try{ 75^AO>gt
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5Deo}(3
int nCount = input.readInt(); ez<V
nStartPos = new long[nCount]; 2"6bz^>}
nEndPos = new long[nCount]; ]Bj2;<@y
for(int i=0;i<nStartPos.length;i++) LS]0p#
{ E.N
nStartPos = input.readLong(); #f<3[BLx
nEndPos = input.readLong(); S`8Iu[Ma
} 76cLf~|d~
input.close(); 50""n7I<%
} H)+QkQb}
catch(IOException e){e.printStackTrace ();} w)C5XX30;
catch(Exception e){e.printStackTrace ();} /V GI@"^v
} uH]oHh!}j
c{ ([U
rXP~k]tC
private void processErrorCode(int nErrorCode) _;M3=MTM9
{ ,pIh.sk7s*
System.err.println("Error Code : " + nErrorCode); /mXxj93UA
} lFl(Sww!\
#/Bg5:
% :h%i|
//停止文件下载 6=:s3I^
public void siteStop() `I.pwst8i-
{ d}Q%I
bStop = true; Q_>W!)p Gz
for(int i=0;i<nStartPos.length;i++) R,ZG?/#uM9
fileSplitterFetch.splitterStop(); k(he<-GF\
jn(%v]
F1meftK
} N "}N>xe2
} J6Vx7
//负责部分文件的抓取 s'|t2`K("
**FileSplitterFetch.java !<24Cy
*/ $*|M+ofQ
package NetFox; cj9C6Y!
m!5Edo-;<
u}b%-:-
import java.io.*; gxx#<=`
import java.net.*; ,Qs%bq{t
LcZ|A;it
[5!dO\-[
public class FileSplitterFetch extends Thread { (9R;-3vY:S
Gk]ZP31u
t{s*,X\b
String sURL; //File URL k!Q{u2
long nStartPos; //File Snippet Start Position eR0$CTSw
long nEndPos; //File Snippet End Position flT6y-d
int nThreadID; //Thread's ID XO+rg&Pu
boolean bDownOver = false; //Downing is over /,`OF/%
boolean bStop = false; //Stop identical WdH/^QvTP
FileAccessI fileAccessI = null; //File Access interface qVfl6q5
tuLNGU
T<-_#}.Hn
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ss%1{s~ok
{ ~Up{zRD"B
this.sURL = sURL; 4(p`xdr}K
this.nStartPos = nStart; s VHk;:e>x
this.nEndPos = nEnd; n*Uk<_WA
nThreadID = id; .G#li(NWH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hD=.rDvO
} |c^?tR<
1jej7p>K
`nKN|6o#x
public void run() ^=5x1<a9$
{ +IO>%
while(nStartPos < nEndPos && !bStop) H8B$#.
{ AgZ?Ry
GC:q6}
@$~IPg[J
try{ n}I?.r@e
URL url = new URL(sURL); &gPP#D6A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "F%JZO51
httpConnection.setRequestProperty("User-Agent","NetFox"); [q Uv|l1
String sProperty = "bytes="+nStartPos+"-"; vxHFNGI
httpConnection.setRequestProperty("RANGE",sProperty); r! HXhl
Utility.log(sProperty); X =%8*_
7f4O~4.[i
:eSsqt9]9
InputStream input = httpConnection.getInputStream(); N#2ldY *
//logResponseHead(httpConnection); =YTcWB
- Z`RKR8C
H>A6VDu
byte[] b = new byte[1024]; vENf3;o0
int nRead; mf)+ 5On
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "i\#L`TkzX
{ A&bj l[s
nStartPos += fileAccessI.write(b,0,nRead); a]T&-#c,}
//if(nThreadID == 1) BjeD4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lm=;Y6'`N
} X fqhD&g
fP V n;
U3N9O.VC
Utility.log("Thread " + nThreadID + " is over!"); n{i,`oQ"
bDownOver = true; Z Cjw)To(
//nPos = fileAccessI.write (b,0,nRead); U2A 82;Z
} )9:5?,SO
catch(Exception e){e.printStackTrace ();} (v%24bv
} RQb}t,
} @1Q-.54a
`/ayg:WSU
P/girce0
//打印回应的头信息 hd u2?v@
public void logResponseHead(HttpURLConnection con) 8M@'A5]
{ [d8Q AO1;)
for(int i=1;;i++) tw>2<zmSi%
{ zD79M
String header=con.getHeaderFieldKey(i); p*&0d@'r
if(header!=null) ?UZt30|1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z sTtSM\Ac
Utility.log(header+" : "+con.getHeaderField(header)); +)iMJ]>
else z8'1R6nq
break; M{Z ;7n'
} m$kQbPlatN
} lOk8VlH<h
{VL@U$'oI
pX ^^0
public void splitterStop() QCF'/G
{ ^w.hI5ua)
bStop = true; ~?AEtl#&"
} C=/B\G/.9
{^ b2nOMv
^Aq0<
} G$+v |z
Zn'tNt/
uI)twry]@
/* RI0^#S_{
**FileAccess.java B-R#?Xn:!I
*//文件访问(定位，写) sa(.Anmlj
package NetFox; ~vFa\7sf
import java.io.*; ( %\7dxiK
$+!dP{
@)?]u U"L
public class FileAccessI implements Serializable{ lGl'A}]#$
AQlB_@ b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &(rWl`eTY`
RandomAccessFile oSavedFile; `X6JZxGyd
long nPos; &$F<]]&
Jpj=d@Of70
vRmn61
public FileAccessI() throws IOException jdP)y]c
{ LdV&G/G-#D
this("",0); S{rltT-
} rP3HR5
&0Yg:{k$
.p&@;fZ
public FileAccessI(String sName,long nPos) throws IOException 8Ojqm#/f
{ K>@yk9)vi
oSavedFile = new RandomAccessFile(sName,"rw"); HUi?\4
this.nPos = nPos; #]kjyT0
oSavedFile.seek(nPos); ttzNv>L,
} 6<._^hyq
"6$V1B0KW
MC}t8L=
public synchronized int write(byte[] b,int nStart,int nLen) XH"+oW
{ /x6p
int n = -1; a/sjW
try{ `hi=y BO
oSavedFile.write(b,nStart,nLen); D(#f`Fj;
n = nLen; G@[8P?M=Z
} 5&&4-
catch(IOException e) 2J ZR"P
{ &X$T "Dp
e.printStackTrace (); =_7wd*,
} Ey&H?OFiP
%9J@##+
N{;!xIv
return n; <v:VA!]
} ;]>kp^C#
/kW Z 8Z
/ (&E
} {^VtD
jT{T#_
.f\LzZ-I:
/* H}^'
**SiteInfoBean.java K4c:k; V
*/ !Zz;;Z
package NetFox; eqo0{e
q$Gs;gz^(
9%/hoA)
public class SiteInfoBean { 9y7N}T6
Z*%;;&?
:Ha/^cC/3
private String sSiteURL; //Site's URL L"bOc'GfQ
private String sFilePath; //Saved File's Path B$4*U"tk
private String sFileName; //Saved File's Name rFRcK>X\L
private int nSplitter; //Count of Splited Downloading File 5)k8(kH
nw+~:c
0#,a#P
public SiteInfoBean() rbw$=bX}
{//nSplitter的缺省值为5 ?[D3-4
//default value of nSplitter is 5 )ZG;.j
this("","","",5); 9wgB JJl7
} rf.pT+g.P
WRh5v8Wz0
q2qi~}l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D*XrK0#Z`
{ YG "Ta|@5
sSiteURL= sURL; Dp@XAyiA[
sFilePath = sPath; DBT4 W/
sFileName = sName; n ~t{]if"
this.nSplitter = nSpiltter; =kjKK
Ot=jwvw
o>el"0rn.h
} l& :EKh
/sE,2X*BT
DJP6Z
public String getSSiteURL() 4"d,=P.{
{ p@<Q?
return sSiteURL; /x<g$!`X
} o-,."|6
54 lD+%E
8Sbz)X
public void setSSiteURL(String value) SQp|
{ 6EqA Y`y
sSiteURL = value; %go2tv:|W
} LU1I `E
ZlT }cA/n
LCF}Y{
public String getSFilePath() s\*L5{kiSl
{ {15j'Qwm
return sFilePath; !b8V&<
} o3J#hQrl
-t`kb*O3`
<_EKCk
public void setSFilePath(String value) N5 ME_)
{ g}an 5a
sFilePath = value; rTPgHK]?l
} 7CIN!vrC|1
K$"#SZEi
AjzTszByu
public String getSFileName() (lk9](;L
{ ]\E"oZ
return sFileName; 5NU{y+
} j\2Qe%d
SSK}'LQ
?=u?u k<-
public void setSFileName(String value) )M0YX?5AR
{ r`H}f#.KR
sFileName = value; agIqca;
} DUp`zW;B
wk(25(1q
Y:^hd809
public int getNSplitter() Hon2;-:]{]
{ |'^s3i&w
return nSplitter; %iyc1]w{
} 1\}vU
DfXkLOGik
5`;SI36"
public void setNSplitter(int nCount) 4TtC~#D:
{ 3I)~;>meo
nSplitter = nCount; N*Y[[N(
} K-qWT7<
} X5 vMY
,jU>V]YC
GQ2GcX(E(
/* aZ#FKp^8H
**Utility.java rRTKF0+
*/ |IgR1kp+.
package NetFox; Xp<q`w0I,
&@~K8*tmK
y>o:5':;'
public class Utility { UXm_-/&b9
,d"T2Hy
&<&tdShI
public Utility() jqUVERbc
{ #s)f3HU>
o9kJ90{D=
,K5K?C$k
} H.5 6
73Dxf -
//线程睡眠 !:{Qbv&T
public static void sleep(int nSecond) wNB?3v{n
{ ^<;W+dWdU
try{ 'L/)9.29
Thread.sleep(nSecond); .N(R~_
} 7e_4sxg'(3
catch(Exception e) ~ua(Qm
{ -[mmT'sS
e.printStackTrace (); JrP`u4f_
} )gpN 5TDd
} pdu1 kL
.K C* (}-
//日志 7HkO:/
public static void log(String sMsg) TWP@\ BQ
{ >AEp\*
System.err.println(sMsg); D T5d]MU
} u>XXKlW:
Fh~9(Y#
*5'8jC"2g
public static void log(int sMsg) YPK@BmAdE
{ rZKh}E
System.err.println(sMsg); -l[H]BAMXy
} 5Tsz|k
} "x$@^
,&[o:jTk
I4Do$&9<D
/* CD1Ma8I8
**TestMethod.java SKG U)Rn;
*/ Np\NStx2
package NetFox; snbXAx1L
SSe;&Jk2d
={g"cx
public class TestMethod { Et6j6gmif
Ey@^gHku\
yg\QtWWM
public TestMethod() D+T/ Z)
{ ///xx/weblogic60b2_win.exe G|cjI*
try{ ,Yag! i>;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ar-Vu{`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FPc`J
SiteFileFetch fileFetch = new SiteFileFetch(bean); <IrhR,@M,L
fileFetch.start(); Q%CrB>|@
} Q Xd`P4a
catch(Exception e){e.printStackTrace ();} (Mc{nFqS
W ?x~"-*
fh#:j[R4e
} Df"PNUwA"
w1Bkz\95
rCJ$Pl9R
public static void main(String[] args) *`a$6F7m4
{ tP_.-//
new TestMethod(); C eEhe
} f]*;O+8$LN
} enk`I$Xx
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