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)); EQ8jxr<p
} WZ'8{XY8
for(int i=0;i<nEndPos.length-1;i++) @a)@1:=Rm
{ x"K<@mR5G
nEndPos = nStartPos[i+1]; _\>?.gg$
} NQ !t`
nEndPos[nEndPos.length-1] = nFileLength; C[gCwDwl
} cPi 3UjY~
} [#$-kd~
THWT\3~,
Xz4!#,z/
//启动子线程 W*e6F?G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Pon 2!$
for(int i=0;i<nStartPos.length;i++) IrjKI.PR
{ mm'n#%\G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QK<sibDI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;hJTJMA6/6
nStartPos,nEndPos,i); )}hp[*C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^IOf%
fileSplitterFetch.start(); "'p:M,:
} nV,qC.z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |8c3%jve
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wo$9$~(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mMjY I1F
nEndPos = " + nFileLength); 4K[E3aA
// fileSplitterFetch[nPos.length-1].start(); YwQxN"
<s2IC_f<+
Bjq1za
//等待子线程结束 +^Eruv+F
//int count = 0; $GNN*WmHw
//是否结束while循环 ~dC)EG
boolean breakWhile = false; {=PO`1H
)&+j#:
thDQ44<#)
while(!bStop) s[NkPh9&
{ 6A;V[3
write_nPos(); ;U<;R
Utility.sleep(500); Q}d6+C
breakWhile = true; '}e_8FS
m"<0sqD;
>K1)XP
for(int i=0;i<nStartPos.length;i++) M9HM:
{ _,"T;i
if(!fileSplitterFetch.bDownOver) O&V}T#8n
{ O;9u1,%w
breakWhile = false; *?Nrx=O*
break; MzL^u8
} *r@7:a5
} b4ZZyw
if(breakWhile) QxH%4 )?
break; rS\j9@=Y4
fPZt*A__
$[T^S
//count++; ' 7+x,TszI
//if(count>4) " JFx
// siteStop(); ?>cx;"xF
} LdwWB `L
I?uU}NK
%%)"W n#`
System.err.println("文件下载结束！"); 5,})x]'x
} {mrTpw
catch(Exception e){e.printStackTrace ();} >8D!K0?E
} 9+nB;vA
Ci4`,
m~'!
//获得文件长度 Yrs7F.Y"
public long getFileSize() NQz*P.q
{ JGOry \
int nFileLength = -1; @X+m,u
try{ $wg5q\Rv
URL url = new URL(siteInfoBean.getSSiteURL()); N4I`6uDgD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nICc}U?k
httpConnection.setRequestProperty("User-Agent","NetFox"); B>rz<bPT
zsFzF`[k
xHq"1Vs=
int responseCode=httpConnection.getResponseCode(); }(A`aB_
if(responseCode>=400) yG)xsY V
{ T$%r?p(s
processErrorCode(responseCode); n^B9Mh@
return -2; //-2 represent access is error >h1 3i@`r
} 1K?RA*aj
C]414Ibi
%V71W3>6WS
String sHeader; `ltc)$
FM;NA{
g5M=$y/H
for(int i=1;;i++) \@;$xdA$
{ 45. -P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (hNTr(z
//Utility.log(in.readLine()); `qnp
sHeader=httpConnection.getHeaderFieldKey(i); G d~ v _
if(sHeader!=null) e+6mbJ7y
{ pFgpAxl
if(sHeader.equals("Content-Length")) qmqWMLfC
{ 5xC4lT/U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WfpQ
break; uNCM,J!#~
} q;Tdqv!Ju
} WD# 96V
else |eykb?j`
break; uzg(C#sp
} J{;XNf =
} KBE3q)
catch(IOException e){e.printStackTrace ();} g%Bh-O9\
catch(Exception e){e.printStackTrace ();} ve($l"T
SW5V:|/
2 j.6
Utility.log(nFileLength); :No`+X[Kq
2(LF @xb
*/c4b:s
return nFileLength; |y9(qcKn$
} v+Eub;m
$`j%z@[g
,1/O2aQ%\0
//保存下载信息（文件指针位置） Zc9@G-
private void write_nPos() oC ?UGY~xL
{ } I>68dS[
try{ !C\$=\$
output = new DataOutputStream(new FileOutputStream(tmpFile)); TOapq9B]
output.writeInt(nStartPos.length); -p.c8B
for(int i=0;i<nStartPos.length;i++) 6&|hpp#[
{ Y`F)UwKK
// output.writeLong(nPos); J,4,#2M8
output.writeLong(fileSplitterFetch.nStartPos); QO2@K1Y
output.writeLong(fileSplitterFetch.nEndPos); ,ZGU\t
} Hb}O/G$a*
output.close(); U\*]cw
} VyX5MVh
catch(IOException e){e.printStackTrace ();} 6$CwH!42F
catch(Exception e){e.printStackTrace ();} Jq>rA
} DW( /[jo\
F+o4f3N
fi%)520
//读取保存的下载信息（文件指针位置） &1/OwTI4J
private void read_nPos() 4>^LEp
{ `%QXaKO-
try{ (#kKL??W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Hjhgu=
int nCount = input.readInt(); &~mJ ).*
nStartPos = new long[nCount]; y0vJ@ %`
nEndPos = new long[nCount]; 5aj%<r
for(int i=0;i<nStartPos.length;i++) I3gl+)Q
{ hL4T7`
nStartPos = input.readLong(); Hg&.U;n
nEndPos = input.readLong(); U!d|5W.{Q
} zh{,.c
input.close(); n%|og^\0
} "C0?s7Y
catch(IOException e){e.printStackTrace ();} wZ4w`|'
catch(Exception e){e.printStackTrace ();} >|X )
} !3F3E8%
"; 1@f"kw
|d$4Fu(M~
private void processErrorCode(int nErrorCode) :FTx#cZ
{ (+yH
System.err.println("Error Code : " + nErrorCode); mT:NC'b<9
} H;nEU@>"Z
fj|b;8_}l
rp9?p%
//停止文件下载 OZc4 -5
public void siteStop() gY'-C
{ *\.8*6*$!
bStop = true; )J*M{Gm6i
for(int i=0;i<nStartPos.length;i++) X[<%T}s#
fileSplitterFetch.splitterStop(); 6k_Uq.<X
6Hbu7r*tm
.k:heN2-x
} Brtsig,4
} "(r%`.l=I
//负责部分文件的抓取 =oBlUE
**FileSplitterFetch.java nU4to
*/ \q($8<
package NetFox; {J1iheuS}
yky%+@2q
(xfh 9=.
import java.io.*; vgE -t
import java.net.*; :8K}e]!c1
3eg6 CdT
4O{G^;
public class FileSplitterFetch extends Thread { cYp/? \
a^={X<K|/
lA%FS]vh
String sURL; //File URL 6Df*wi!jI
long nStartPos; //File Snippet Start Position Jz}`-fU`
long nEndPos; //File Snippet End Position -woFKAy`
int nThreadID; //Thread's ID zYrJHn#vB
boolean bDownOver = false; //Downing is over /GVjesN
boolean bStop = false; //Stop identical 0-~s0R89A
FileAccessI fileAccessI = null; //File Access interface +OqEe[Wk#
"fr{:'HX
Nm !~h|3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pdB\D
{ NVghkd
this.sURL = sURL; EK= y!>
this.nStartPos = nStart; Lb)rloca
this.nEndPos = nEnd; |h}4J
nThreadID = id; ,-hbwd~M
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (H5#r2h%Y
} ,{mv6?_
e!PB3I
%ufh
public void run() NT0n[o^
{ ]J[d8S5
while(nStartPos < nEndPos && !bStop) S)g:+P
{ 81"` B2
Pz34a@%"
=[8K#PZ$w
try{ #|4G,!
URL url = new URL(sURL); =\_gT=tZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m% 3D
httpConnection.setRequestProperty("User-Agent","NetFox"); HdgNy\
String sProperty = "bytes="+nStartPos+"-"; `LNhamp
httpConnection.setRequestProperty("RANGE",sProperty); "w$,`M?2
Utility.log(sProperty); ?m5EXe
*L9v(Kc
~|9VVeE
InputStream input = httpConnection.getInputStream(); #CPLvg#
//logResponseHead(httpConnection); 7UY4* j|[C
s;YbZ*oaMe
J^`5L7CO
byte[] b = new byte[1024]; &&m3E=K!^
int nRead; /!2`pv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) d|oO2yzWv
{ ]/kpEx
nStartPos += fileAccessI.write(b,0,nRead); ]iGeqwT
//if(nThreadID == 1) ;1[Z&Uv8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8q%y(e
} 1cv~_jFh
F$(ak;v}
0Dna+V/jI
Utility.log("Thread " + nThreadID + " is over!"); g9q}D-
bDownOver = true; y] c1x=x
//nPos = fileAccessI.write (b,0,nRead); hVmnXT 3Z
} t"Ci1"U
catch(Exception e){e.printStackTrace ();} En1LGi4#
} X3a9-
} (w#t V*
(De{r|
/zt M'
//打印回应的头信息 zxx\jpBBk
public void logResponseHead(HttpURLConnection con) xI1{Wo*2C}
{ c\2rKqFD8
for(int i=1;;i++) (T0MWp0
{ k'PvTWR
String header=con.getHeaderFieldKey(i); 4")`}T
if(header!=null) 2?GMKd)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?"r=08
Utility.log(header+" : "+con.getHeaderField(header)); 3r,~-6
else 'St6a*
break; RSe4lw
} Go)g}#.&
} ^t5My[R
>9rZVNMU
?9a%g\`?:
public void splitterStop() F^'$%XKV
{ YO.+-(
bStop = true; 8k95IJR1
} fCx(
+x=)Kp>
<|4$TH^t
} >P:X\5Oj
cu($mjC@T
xsB0LUt
/* vo`&
**FileAccess.java '"fJA/O
*//文件访问(定位，写) q6)fP4MQ]
package NetFox; kFwFPK%B
import java.io.*; 6ki2/ Q
^APtV6g
z'"7zLQ
public class FileAccessI implements Serializable{ >4jE[$p]"
W\k8f+Ke
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?:J_+?{E
RandomAccessFile oSavedFile; H#_Zv]
long nPos; Z;Hkx1
+q}t%K5
8^>c_%e}
public FileAccessI() throws IOException lP3|h*
{ Si>38vCJ*
this("",0); VFL^-tXnA^
} "vSKj/]
A,9JbX
X}v*"`@Q
public FileAccessI(String sName,long nPos) throws IOException 7Hr_ZwO/^
{ C)z4Cn9#
oSavedFile = new RandomAccessFile(sName,"rw"); "0PrdZMx
this.nPos = nPos; W~'xJ
oSavedFile.seek(nPos); qK a}O*
} GYfOwV!zB
[|OII!"
O`9c!_lis
public synchronized int write(byte[] b,int nStart,int nLen) +QU>D:l
{ Sp80xV_B
int n = -1; (c(F1=K
try{ ZpVkgX4
oSavedFile.write(b,nStart,nLen); rk W7;!
n = nLen; >\Dy
} z}ar$}T
catch(IOException e) k0e}`#t
{ %hsCB .r>|
e.printStackTrace (); i]%f94
} e~SK*vR%]
Nnl3r@
YpDJ(61+
return n; z6iKIw $
} RW L0@\
+7H)s
$V(]z`b&
} TU0-L35P1
D=-}&w_T"
v.Ba
/* Q?k*3A
**SiteInfoBean.java {R!yw`#^B
*/ ZwS:Te9-
package NetFox; B-Jd|UE`u
sgp.;h'
'RMUjJ-!
public class SiteInfoBean { NS[eQ_rT
%xg+UW }
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private String sSiteURL; //Site's URL eBrNhE-[G]
private String sFilePath; //Saved File's Path D*%am|QL
private String sFileName; //Saved File's Name eWcqf/4?"
private int nSplitter; //Count of Splited Downloading File [CI&4)#
w(Z?j%b
32[}@f2q
public SiteInfoBean() KdR4<qVV}
{//nSplitter的缺省值为5 a{]=BY oL
//default value of nSplitter is 5 \X8b!41
this("","","",5); *y*tI}
} "CT}34l
N-M.O:p
Tn}`VW~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6h;(b2p{
{ 8)X9abC
sSiteURL= sURL; c* {6T}VZr
sFilePath = sPath; r(>S
sFileName = sName; <k:I2LF_
this.nSplitter = nSpiltter; I\.|\^
5naFnm7%
1Z# $X`
} gJ6`Kl985O
LTWkHyx
UCLM*`M
public String getSSiteURL() 1INX#qTZ
{ z'q~%1t
return sSiteURL; S}@7Z`
} y&NqVR=
}`"}eN @,
0^ODJ7
public void setSSiteURL(String value) fu"cX;
{ kamQZzPe
sSiteURL = value; )d2Z g
} 1B~O!']N<
>v:ex(y0
ra$:ibLN
public String getSFilePath() PJ.\)oP
{ E]@&<TFq
return sFilePath; 9F/I",EA
} u\*9\G
QtW9!p7(
!#KKJ`uB"
public void setSFilePath(String value) ku]5sd >b
{ cc[(w #K
sFilePath = value; <Ua~+U(FR0
} 3B1\-ry1M
pDR~SxBXr
O?e9wI=H
public String getSFileName() URsx>yx
{ *dBeb
return sFileName; Y Zj-%5
} L`+[mX&2B
s6 yvq#:
k~>(XG[x&
public void setSFileName(String value) C%o|}iv"
{ mU/o%|h
sFileName = value; *g(d}C!
} a"vzC$Hxd
v)5;~.+%
"V|Rq]_+%
public int getNSplitter() }t)+eSUA
{ jx}&%p X
return nSplitter; P<]U
} .WF"vUp
kKyU?/aj
b"I#\;Ym
public void setNSplitter(int nCount) M)bQvjj
{ cgb>Naa<
nSplitter = nCount; FOiwA.:0
} ea3w
} :U?g']`Z##
ReaZg ?:h
[3Q0KCZ0(
/* :aNjh
**Utility.java =6sP`:
*/ 7[m+r:y
package NetFox; 0+>g/>
`d_T3^ayu
'Ea3(OsuXn
public class Utility { fCY|iO0.t
#w{`6}p
I{IB>j}8
public Utility() gT)(RS`_)
{ uN%Cc12
x"2p5T7*>
AzU:Dxr>.G
} Cd%5XD^
, 'pYR]3
//线程睡眠 L ]')=J+
public static void sleep(int nSecond) KXPCkNIN!
{ 6N@=*0kh-
try{ *l_a=[<[
Thread.sleep(nSecond); '}hSh
} \RDN_Z
catch(Exception e) u3h(EAH>
{ ('z=/"(l
e.printStackTrace (); 7Jb&~{DVk
} $[T~<I
} $JFjR@j
FWW4n_74
//日志 0)dpU1B#M
public static void log(String sMsg) (TeH)j!
{ (PpY*jKR
System.err.println(sMsg); DI0& _,
} aCU[9Xr?
+Y?Tri
-h8mJ D%Oi
public static void log(int sMsg) )q$[uS_1[
{ 4phCn5
System.err.println(sMsg); 0AnL]`"t.3
} cj>@Jx}]M
} r]e{~v/
2zj` H9
WAn@8!9
/* |r@;ulO
**TestMethod.java O@$>'Z
*/ "@x(2(Y&
package NetFox; +wQ5m8E
Ec7xwPk
A+/Lt>+AS
public class TestMethod { \9+,ynJH8z
dX?j/M-
G]B0LUT6c
public TestMethod() HS=w9:,
{ ///xx/weblogic60b2_win.exe 29Uqdo
try{ h%j4(v}r{C
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); BFNO yv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,88B@a
SiteFileFetch fileFetch = new SiteFileFetch(bean); dz#"9i5b
fileFetch.start(); oCo~,~kTR
} .\bJ,of9
catch(Exception e){e.printStackTrace ();} dOD(<
lr&2,p<
Md6u4c
} ~criZI/
X0*+]tRg
H [+'>Id:
public static void main(String[] args) @;EQ{d
{ ;8H&FsR
new TestMethod(); C?. ;3 h
} =o@}~G&HA
} P~(&lu/;P
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