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)); X+L) -d
} ,YTIC8qKr
for(int i=0;i<nEndPos.length-1;i++) U$]|~41#
{ vE@!{*
nEndPos = nStartPos[i+1]; ~(!XY/0e
} ?Nf>]|K:Q
nEndPos[nEndPos.length-1] = nFileLength; j`^$#
} 61puqiGG^
} @k[R/,#'[t
L^2FQti>
B~o\+n
//启动子线程 wW>zgTG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )[0T16
for(int i=0;i<nStartPos.length;i++) f` =CpO*
{ _XJ2fA )
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (" LQll9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +a-6Q ~
nStartPos,nEndPos,i); VE+IKj!VG0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '!l1=cZD
fileSplitterFetch.start(); 4wC+S9I#E^
} d ;vT ~;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6"Bic rY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $o$ maA0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~P~
nEndPos = " + nFileLength); M@ed>.
// fileSplitterFetch[nPos.length-1].start(); ;};wq&b#
^O^l(e!3
lY|Jr{+Ln
//等待子线程结束 y_\p=0t8
//int count = 0; }*.0N;;C
//是否结束while循环 ?A(QyaKz
boolean breakWhile = false; xX*H7#
x77l~=P+!
fP.F`V_Y
while(!bStop) PV|uPuz
{ ^Ge+~o?x
write_nPos(); T]2q?;N
Utility.sleep(500); :'#TCDlOb
breakWhile = true; ]-ZEWt6lsc
me[DmiM,
7AYd!n&S
for(int i=0;i<nStartPos.length;i++) 0-~\ W(
{ Fx-8M!
if(!fileSplitterFetch.bDownOver) 9U$EJN_G
{ $<:E'^SAS
breakWhile = false; [9Ss#~
break; sC9&Dgkk
} I\YV des#
} w@N
if(breakWhile) h;6lK$!c
break; ByCnD
`jwa<N4e@
7o8{mp'_
//count++; 31/Edd"]
//if(count>4) s kg*
// siteStop(); os/vtyP:a
} [IK )
%-d]X{J:
76u&EG%
System.err.println("文件下载结束！"); T49zcJf;
} g!-,]
catch(Exception e){e.printStackTrace ();} kF/9-[]$g,
} rETRTp0HT
e^.Fa59
(V4 ~`i4V
//获得文件长度 &hRvol\J
public long getFileSize() .A6(D$O k
{ K)J(./
int nFileLength = -1; 7b<yVP;{
try{ ULQMG'P^D
URL url = new URL(siteInfoBean.getSSiteURL()); hWX% 66
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )B[0JrcE
httpConnection.setRequestProperty("User-Agent","NetFox"); HD(.BW7
"HPB!)C8(
s`0QA!G{-
int responseCode=httpConnection.getResponseCode(); rF]h$Z8o
if(responseCode>=400) % LJs
{ J>/w5$h5
processErrorCode(responseCode); \Ym5<];E
return -2; //-2 represent access is error x g0iN'e'K
} I'|$}/\`
g]*#%Xa
L:FoSCN Y(
String sHeader; mauI42
k+ze74_"
fMOU$0]$<
for(int i=1;;i++) R~Ne|V2
{ k1QpKn*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fl\ly`_
//Utility.log(in.readLine()); j$+nKc$
sHeader=httpConnection.getHeaderFieldKey(i); TA{\PKA)
if(sHeader!=null) ]Ux<aiY]a
{ 5H ue7'LS
if(sHeader.equals("Content-Length")) b#X^=n2
{ >Q(3*d >
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?mwD*LN3o
break; )b:7-}d
} Z?\2F%
} p\bDY
else ~$~5qwl
break; utIX %0
} Nqu>6^-z0
} t25,0<iW
catch(IOException e){e.printStackTrace ();} e d<n9R
catch(Exception e){e.printStackTrace ();} kkQVNphc
}I :OsAw
XHK70: i
Utility.log(nFileLength); ^/r7@:
ho$+L
hRCed4qA
return nFileLength; /Z$&pqs!
} ~8]NK&J
dxmE3*b`
YxP&7oq
//保存下载信息（文件指针位置） 7(5 4/
private void write_nPos() >"C,@cN}B
{ 62Z#YQ}x
try{ R00eisd
output = new DataOutputStream(new FileOutputStream(tmpFile)); )BwjZMJ.N
output.writeInt(nStartPos.length); .,OVzW
for(int i=0;i<nStartPos.length;i++) sD=n95`v
{ Cvf[/C+
// output.writeLong(nPos); PS[+~>%
output.writeLong(fileSplitterFetch.nStartPos); mFi&YpHu3
output.writeLong(fileSplitterFetch.nEndPos); %T~ig[GstX
} 6Aku1h
output.close(); tQjLOv+?=
} } q$ WvY/
catch(IOException e){e.printStackTrace ();} =F@Wgn,
catch(Exception e){e.printStackTrace ();} (JM5`XwM
} GSRVe/[
!7kG!)40
O)jWZOVp >
//读取保存的下载信息（文件指针位置） T87m?a$
private void read_nPos() g4l !xT
{ ](s'L8(x
try{ 6*3.SGUY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RS^lKJ1 U
int nCount = input.readInt(); L>3x9
nStartPos = new long[nCount]; hy`?E6=9+
nEndPos = new long[nCount]; gy_>`16K
for(int i=0;i<nStartPos.length;i++) lqm1!5dt
{ h]TQn)X]
nStartPos = input.readLong(); |y2w9n0D
nEndPos = input.readLong(); k@'#@ t
} smnSDS
input.close(); MP>dW nl
} `-p:vq`
catch(IOException e){e.printStackTrace ();} $GTU$4u
catch(Exception e){e.printStackTrace ();} fe9LEM8j
} ;t|Ii8Ne
^G.B+dG@`x
P9vA7[
private void processErrorCode(int nErrorCode) /%;mqrdk
{ {62n7'U{
System.err.println("Error Code : " + nErrorCode); QC9eUYe
} fP(d8xTx2y
}3OKC2K~
MZT23[+
//停止文件下载 6Q${U7%7
public void siteStop() y$_eCmq
{ `nZ)>
bStop = true; -$dXE+&
for(int i=0;i<nStartPos.length;i++) e=+?K5q{P(
fileSplitterFetch.splitterStop(); 28UU60
JW3B'_0
/so8WRu.
} iLkZ"X.'|1
} TZY3tUx0|G
//负责部分文件的抓取 {qN 5MsY
**FileSplitterFetch.java %'X[^W
*/ 6x%h6<#xh*
package NetFox; |\7 ET[Xq
,&R/4:I
-}KC=,]vh
import java.io.*; @*6 C=LL
import java.net.*; Z7=`VNHc
WjlZ6g2i
/N&CaH\;^$
public class FileSplitterFetch extends Thread { a+%6B_|\
/JWGifH
ybY]e; v*O
String sURL; //File URL ;e1ku|>$
long nStartPos; //File Snippet Start Position 4#:W.]U8
long nEndPos; //File Snippet End Position ;{U@qQD7
int nThreadID; //Thread's ID ]3X@_NYj
boolean bDownOver = false; //Downing is over y9>ZwYN
boolean bStop = false; //Stop identical ~2gG(1%At9
FileAccessI fileAccessI = null; //File Access interface %3ICI
~Hr}]
]hFW73FV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }#&#^ B#?O
{ TztAZ2C
this.sURL = sURL; ''0fF_P
this.nStartPos = nStart; W7 #9jo
this.nEndPos = nEnd; p_${Nj
nThreadID = id; i:OK8Q{VI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a-|*?{o
} Y7*U:I+N
Aj+2;]M
V7Ek-2M
public void run() iqe%=%ZR
{ SAyufLEv,
while(nStartPos < nEndPos && !bStop) V0P>YQq9s
{ cT!\{~
_s .G
v5QqS8u_C
try{ 2AO~HxF
URL url = new URL(sURL); jAm3HI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +PcmJ
httpConnection.setRequestProperty("User-Agent","NetFox"); c+hQSm|bf)
String sProperty = "bytes="+nStartPos+"-"; paD!Z0v&
httpConnection.setRequestProperty("RANGE",sProperty); 7r~~Y%=C|
Utility.log(sProperty); B4i!/@0s
g.zEn/SM
yL2o}ZbS
InputStream input = httpConnection.getInputStream(); F)'.g d
//logResponseHead(httpConnection); 0a-0Y&lQm
Stu4t==U
\uza=e
byte[] b = new byte[1024]; t3&LO~Ye
int nRead; *fn*h[pV&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W8KDX_vGJ
{ d ysC4DS
nStartPos += fileAccessI.write(b,0,nRead); ,I%g|'2
//if(nThreadID == 1) 93` AWg/T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3v5%y'
} X;"Sx#U
\ywXi~+kUv
iC98_o_9
Utility.log("Thread " + nThreadID + " is over!"); 2-C!jAfd
bDownOver = true; wv\w;'
//nPos = fileAccessI.write (b,0,nRead); L;'"A#Pa
} ]y1OFKYv
catch(Exception e){e.printStackTrace ();} Vp3ZwS
} TwVlg;
} \<y#R~7s
8>WC5%f*
2&^]k`Aj6D
//打印回应的头信息 ihP|E,L=L
public void logResponseHead(HttpURLConnection con) (?(zH3
{ =Q+= f
for(int i=1;;i++) /7t>TYip!
{ =1Oj*x@*4
String header=con.getHeaderFieldKey(i); eFL=G%
if(header!=null) xx{PespNt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %0,#ADCqOe
Utility.log(header+" : "+con.getHeaderField(header)); R}4So1
else 2IKnhBSV3
break; A.EbXo/
} TiO"xMX
} JAQb{KefdO
"6us#T
FMClSeO7
public void splitterStop() S=e{MI
{ uoX:^'q
bStop = true; EB2!HpuQ3
} -wSg2'b4E
YYu6W@m]
:qIXY/
} 3 %|86:*
3P^sM1
'F$l{iR
/* Od%"B\
**FileAccess.java O0pDd4)"
*//文件访问(定位，写) 49dd5ddr
package NetFox; b#hDHSdZ,
import java.io.*; lMg+R<$~I
i5K[>5
bS"fkf9
public class FileAccessI implements Serializable{ O2f-5Y$@
Ft;^g3N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f'VX Y-
RandomAccessFile oSavedFile; i-6F:\;
long nPos; <oX7P69
h >s!K9
%Cv D-![0
public FileAccessI() throws IOException !`M|C?b
{ ` M3w]qJ<}
this("",0); % <qw
} t`,`6@d
aW`Lec{.
=yyp?WmC8
public FileAccessI(String sName,long nPos) throws IOException Bb}fj28
{ A3iFI9Iv
oSavedFile = new RandomAccessFile(sName,"rw"); }`,t$NV`
this.nPos = nPos; h?;T7|^
oSavedFile.seek(nPos); TG+VEL |T
} 4*cU<
#[`:'e
vWf; 'j
public synchronized int write(byte[] b,int nStart,int nLen) < VSA
{ @qnD=mE
int n = -1; 6w(6}m.L^
try{ U}PiY"S<
oSavedFile.write(b,nStart,nLen); x*nSHb
n = nLen; !qN||mCH
} "G@g" gP
catch(IOException e) mM-8+H?~b
{ ktdW`R\+
e.printStackTrace (); $+3}po\
} X7i/fm{l'
kT!9`S\
pFHz"]
return n; 9uBM<
} ~(IB0=A{v
ZObhF#Y9
t{WzKy
} O2BDL1o
LM-J !44
lAJxr8 .
/* 4W)B'+ZK8
**SiteInfoBean.java ^n"OL*ipG
*/ Bxfc}vC.
package NetFox; ;Mpy#yIU.
$W9{P;
$[/&74#0HX
public class SiteInfoBean { !/3B3cG
!cAyTl(_
\&iP`v`K
private String sSiteURL; //Site's URL `P8Vh+7u
private String sFilePath; //Saved File's Path B&.FOO
private String sFileName; //Saved File's Name u(wGl_
private int nSplitter; //Count of Splited Downloading File }c}| $h^Y
[h34d5'w
d~:!#uWyFk
public SiteInfoBean() J<dVTxK12
{//nSplitter的缺省值为5 Q'YH>oGh^
//default value of nSplitter is 5 \a6^LD}B
this("","","",5); Z]j*9#G1s
} .72S oT
sh`s/JRf
S!G(a"<W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /`6ZAom9
{ "gne_Ye.
sSiteURL= sURL; qLT>Mz)$%
sFilePath = sPath; 3`ELKq
sFileName = sName; j S?xk
this.nSplitter = nSpiltter; KOp162X>r
'F_8j;
X(\fN[;
} weE/TW\e
<Gt2(;
UF<uU-C"
public String getSSiteURL() fe_yqIdk
{ $n+w$CI)
return sSiteURL; ;ml)l~~YU
} LK, bO|
Pp`*]Ib
bVL9vNK
public void setSSiteURL(String value) 3plzHz,x
{ "(3BvMA&!9
sSiteURL = value; 8-_QFgY
} _',prZ*
nM-h&na{s
mi)LP?q
public String getSFilePath() _/s(7y!
{ Lv'D^'I
return sFilePath; 6C]1Q.f;
} u9}1)9
B]Y}Hu
bV8!"{
public void setSFilePath(String value) z6?)3'
{ lmxr oHE
sFilePath = value; B,K>rCZ/
} FcRW;e8-
_jNj-)RB_
v}tag#f5>?
public String getSFileName() @W^| ?
{ P '>SmQ
return sFileName; }p!HT6 tZ
} /u0' 6V
5fm?Lxr&?
NDs!a
public void setSFileName(String value) niqN{
{ `xywho%/Y
sFileName = value; 6q]5Es<
} 72X0Tq 4
0qo)."V{
<YOLxR
public int getNSplitter() AjT%]9 V?
{ Xy@7y[s]
return nSplitter; Pj4/xX
} *+\SyO
SnFk>`
o4%y>d)
public void setNSplitter(int nCount) g"?Y+j
{ 59%tXiO
nSplitter = nCount; wmTq` XH)
} AwTJJ0>
} \uXcLhXN
Z7_ zMM
)E,\H@A
/* y-j\zK
**Utility.java rc/nFl6#
*/ 8:#rA*Y
package NetFox; Pp|*J^U 4
}yJ$SR]t
w^#L9i'v'
public class Utility { (vB<%l.&
@E-\ J7 yh
}t;(VynV)
public Utility() V0%V5>
{ -W<vyNSr
^.hoLwp.
+{/*z
} Q^q1ns;r
~",`,ZXQy
//线程睡眠 :{ur{m5bX
public static void sleep(int nSecond) 8Y_ol#\L
{ 3Te^
try{ 9:!gI|C
Thread.sleep(nSecond); Z-U-N
} '2laTl]`
catch(Exception e) 2OwV^-OG
{ N @#c,,
e.printStackTrace (); EM/@T}
} <TE%Prd}`
} 9{$<0,?
rS?pWTg"8
//日志 zt<WXw(
public static void log(String sMsg) Y= ]dvc
{ %<\6TZr
System.err.println(sMsg); !Yw3 d
} TD9;kN1`
Xu>r~^w=S
MzP7Py 8.
public static void log(int sMsg) OZIW_'Wm/
{ 24/XNSE,-
System.err.println(sMsg); w,Lvt }
} oh KCdT~
} &E40* (C
8>.J1C
P{5-Mx!{&
/* 6}(J6T46M[
**TestMethod.java p<&Xd}]"^W
*/ W0C@9&pn6
package NetFox; 4WN3=B
dTL5-@
R-RDT9&<
public class TestMethod { :mS# h@l
3"kdjOB
9Li%KOY
public TestMethod() `iJhG^w9M
{ ///xx/weblogic60b2_win.exe Mze;k3
try{ =;3fq-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HoLv`JA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Sje wuIi1
SiteFileFetch fileFetch = new SiteFileFetch(bean); |hO~X~P
fileFetch.start(); c(/VYMJZ&
} g >'p>}t
catch(Exception e){e.printStackTrace ();} rx5B=M
xy<`#
90# ;?#
} I"t(%2*q
#9m$ N
3GmeD/6
public static void main(String[] args) %',F
{ qA:#iJ8w
new TestMethod(); )$&dg2[
} if)Y9:{r^
} k`{@pt.
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