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)); 4e(9@OLP
} !T#8N7J>
for(int i=0;i<nEndPos.length-1;i++) #VQGN2bK.
{ =0@d|LeZ
nEndPos = nStartPos[i+1]; Hnd9T(UB
} ?c=R"Yg$
nEndPos[nEndPos.length-1] = nFileLength; i(&6ys5
} l ))~&
} 6]@|7|N>X
6*(h9!_T1
RAD4q"}k
//启动子线程 ery?G-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `aO@N(
for(int i=0;i<nStartPos.length;i++) (IoPU+1b
{ SBN_>;$c5}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bgzT3KZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rr07\;
nStartPos,nEndPos,i); *Lb(urf
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |`)V^e_
fileSplitterFetch.start(); )L(d$N=Bd
} J1c&"Oh
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RV#uy]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u]]5p[|S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v8'`gY
nEndPos = " + nFileLength); c@o/Cv
// fileSplitterFetch[nPos.length-1].start(); EhP&L?EL
RP@idz
r/q1&*T
//等待子线程结束 {z[HNSyRs
//int count = 0; fssL'DD
//是否结束while循环 AZ]SRz9mKY
boolean breakWhile = false; gH{\y5%rO
i2ml[;*,N
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while(!bStop) (krG0S:0Q
{ /wxxcq
write_nPos(); >A'!T'"~
Utility.sleep(500); CQuvbAo
breakWhile = true; ubCJZ"!
n%ArA])_&
+zdq+<9X
for(int i=0;i<nStartPos.length;i++) Y`O}]*{>8R
{ J>|:T
if(!fileSplitterFetch.bDownOver) eUw;!Du
{ HG3>RcB
breakWhile = false; YK+Z0ry
break; \w_[tPz}
} 8}0y)aJ
} rHdP4:n
if(breakWhile) __n"DLW
break; ,Y5 4(>>%
qmyZbo|8&
3Co>3d_
//count++; ZU@jtqq
//if(count>4) knZd}?I*
// siteStop(); juYt =
} ghQsS|)p.
GeTCN
i1&noRGl
System.err.println("文件下载结束！"); 'u%;6'y
} (xJBN?NRO
catch(Exception e){e.printStackTrace ();} K{h]./%
} |Qq'_4:
}4`YdN
62'0)Cy^
//获得文件长度 {73DnC~N
public long getFileSize() `fVA.%
{ [~JN n
int nFileLength = -1; r~a}B.pj
try{ ky"7 ^
URL url = new URL(siteInfoBean.getSSiteURL()); |'(IWU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :9>nY
httpConnection.setRequestProperty("User-Agent","NetFox"); %tjEVQa
wQ95tN
$(hZw
int responseCode=httpConnection.getResponseCode(); \EqO;A%<
if(responseCode>=400) '7%9Sqx
{ DvKMb-*S
processErrorCode(responseCode); 4K,&Q/Vdd7
return -2; //-2 represent access is error |LhuZ_;1xo
} oOvbel`;
}zLE*b,
^`9OA`2
String sHeader; WV5R$IqY
eLWzd_ln
iWsIc\!+,
for(int i=1;;i++) E_#&L({|@
{ 8A=(,)`}9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =Ih_[$1dw
//Utility.log(in.readLine()); @ZWKs
sHeader=httpConnection.getHeaderFieldKey(i); 0_)\e
if(sHeader!=null) D-/A>
{ ^B>6!
if(sHeader.equals("Content-Length")) s4\2lBU?
{ KA7nncg;,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5,3h'\ "!
break; U/;Vge8{
} >3/<goXk7
} j jQ=
else ?uLqB@!2
break; %1<|.Dmd
} j&r5oD;
} x :s-\>RcA
catch(IOException e){e.printStackTrace ();} 78kk"9h'
catch(Exception e){e.printStackTrace ();} 4?cg6WJ'6
0&)4^->c
.#SWfAb2h
Utility.log(nFileLength); gw-l]@;1
[Fe5a
L=>N#QR7
return nFileLength; b^1!_1c
} #gP\q?5Ov
aO{k-44y
on~rrSK
//保存下载信息（文件指针位置） @YRBZ6FH
private void write_nPos() b=sc2)3?
{ iqpy5
try{ |1EM )zh6
output = new DataOutputStream(new FileOutputStream(tmpFile)); i4l?q#X
output.writeInt(nStartPos.length); Y,{Xv
for(int i=0;i<nStartPos.length;i++) !.!Ervi!N
{ SI\zW[IL
// output.writeLong(nPos); MCvjdc3:
output.writeLong(fileSplitterFetch.nStartPos); 9ItsK
output.writeLong(fileSplitterFetch.nEndPos); ey:3F%
} ~R3@GaL1
output.close(); rZ<@MV|d
} XvWUJ6M
catch(IOException e){e.printStackTrace ();} hl8[A-d(R
catch(Exception e){e.printStackTrace ();} =MA$xz3
} !fY'^Ya?
ka655O/)&
PKk_9Xd
//读取保存的下载信息（文件指针位置） XfharJ_b
private void read_nPos() S'q (Qo
{ I;9>$?t[
try{ V|Smk;G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A\YP}sG1
int nCount = input.readInt(); !CUrpr/*
nStartPos = new long[nCount]; rF'q\tJDz
nEndPos = new long[nCount]; ;>bcI).
for(int i=0;i<nStartPos.length;i++) e~oI0%xl^
{ cE'MSB
nStartPos = input.readLong(); \G:\36l
nEndPos = input.readLong(); |bA\>%~
} v25]}9/C
input.close(); N$i!25F`
} Xgou7x<
catch(IOException e){e.printStackTrace ();} eT0Yp
catch(Exception e){e.printStackTrace ();} llN#4D9s
} VG'M=O{)3
j&~`H:=E
(Rj'd>%c
private void processErrorCode(int nErrorCode) 8`M) r'5
{ >NDI<9<'0}
System.err.println("Error Code : " + nErrorCode); j#6@cO'`
} /x\{cHAt8J
Z#+lwZD
Mwm9{1{
//停止文件下载 <a_ytSoG1
public void siteStop() vf^`'
{ 2Tt^^Lb
bStop = true; hUR>NUK@8
for(int i=0;i<nStartPos.length;i++) (@X].oM^y
fileSplitterFetch.splitterStop(); \+3amkBe
Ts)ox}rYVm
H+lBb$
} 6)5Akyz4V
} `0)'&HbLY
//负责部分文件的抓取 S3fyt]pp
**FileSplitterFetch.java QY7Thnp1
*/ RvXK?mL4F
package NetFox; =hAH6C
)y#~eYn
og$%`o:{
import java.io.*; u*"mdL2
import java.net.*; <h"07.y
%Eq4>o?D
9fhgCu]$
public class FileSplitterFetch extends Thread { 09_5niaz[
xPp\OuwK
u#bd*(
String sURL; //File URL @hVF}ybp
long nStartPos; //File Snippet Start Position }eLnTi{
long nEndPos; //File Snippet End Position K3I|d;Y~X!
int nThreadID; //Thread's ID N*$L#L$*
boolean bDownOver = false; //Downing is over :=cZ,?PQp1
boolean bStop = false; //Stop identical +3wVcL
FileAccessI fileAccessI = null; //File Access interface _VM()n;
kKlcK_b;
hH3~O`~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7FBaN7l
{ +BaZl<ZP1s
this.sURL = sURL; xp68-&
this.nStartPos = nStart; gq|]t<'
this.nEndPos = nEnd; QKVFH:"3
nThreadID = id; {wq~+O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [gE_\=FSKu
} pf@H;QS`
^f?>;,<&
s%OPoRE
public void run() lHI;fR
{ \.l8]LH
while(nStartPos < nEndPos && !bStop) zMI_8lNz
{ ?P>3~3 B
7,BULs\g
@SX-=Nr
try{ tA{B~>
URL url = new URL(sURL); *rH#k?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [19QpK WM
httpConnection.setRequestProperty("User-Agent","NetFox"); $AyE6j_1gX
String sProperty = "bytes="+nStartPos+"-"; 5S/YVRXq
httpConnection.setRequestProperty("RANGE",sProperty); G.l ~!;
Utility.log(sProperty); QoBM2QYO
\:Vm7Zg
8{)j"rghah
InputStream input = httpConnection.getInputStream(); [==x4Nb
//logResponseHead(httpConnection); )z=L^ot
5'%nLW7;O
QTLGM-Z
byte[] b = new byte[1024]; `~;`q
int nRead; W^8MsdM
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hztxsvw
{ Zv|TvlyT"
nStartPos += fileAccessI.write(b,0,nRead); 1wTPT,k
//if(nThreadID == 1) AdGDs+at,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :JD*uu
} sn-P&"q
!E.CpfaC
dK d"2+fH
Utility.log("Thread " + nThreadID + " is over!"); c\DMeYrg
bDownOver = true; F|bg2)|du8
//nPos = fileAccessI.write (b,0,nRead); H{U(Rt]K
} ?)V|L~/
catch(Exception e){e.printStackTrace ();} W'! I+nh
} q#_<J1)z
} %*a%F~Ss
U%V4@iz~\m
)uRR!<"~
//打印回应的头信息 v7b+
public void logResponseHead(HttpURLConnection con) =Ohro'
{ S=_*<[W%4
for(int i=1;;i++) Ev]oPCeA
{ b"pN;v
String header=con.getHeaderFieldKey(i); y"Ios:v@-
if(header!=null) 9][A1+"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Vu5Djx'
Utility.log(header+" : "+con.getHeaderField(header)); `;)op3A'
else XE($t2x,M
break; w[]\%`69}Z
} Vi<6i0
} IylfMwLC
<[A;i
@d_9NOmNT
public void splitterStop() ->rudRQ
{ @pN6uDD}R
bStop = true; &xE+PfX
} <RCeY(1
1k!$#1d<
x\b+B
} 1 &-%<o
U[G5<&Z^
Y/]J0D
/* yC\!6pg
**FileAccess.java U-pBat.$'C
*//文件访问(定位，写) ;nw}x4Y[
package NetFox; 6F; |x
import java.io.*; 51'{Jx8
iJb-F*_y
^2LqKo\T
public class FileAccessI implements Serializable{ I<!,_$:
LX</xI08W
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M9QxF
RandomAccessFile oSavedFile; e$N1m:1*
long nPos; %o_CD>yD
d(F4-kBd
UQO?hZ!y/.
public FileAccessI() throws IOException cv9-ZOxJ
{ ,lQfsntk'
this("",0); +m4?a\U
} "#]V^Rzxh
N >k,"=N/
t'*2)U
public FileAccessI(String sName,long nPos) throws IOException @!mjjeG+1
{ +t}<e(
oSavedFile = new RandomAccessFile(sName,"rw"); O4T_p=Xc
this.nPos = nPos; +?+iVLr!l}
oSavedFile.seek(nPos); QA#Jx
} w%eEj.MI|i
Rip[
J-W8wCq`
public synchronized int write(byte[] b,int nStart,int nLen) %i@Jw
{ 6B@{X^6y
int n = -1; j]
try{ J>^KQ
oSavedFile.write(b,nStart,nLen); 2qPQ3-'
n = nLen; >qci$
} Z'_EX7r
catch(IOException e) T9]:, z
{ 0ae}!LO
e.printStackTrace (); +Ec@qP R&
} s3oQ( wC %
|1UJKJwX
i~.9B7hdE
return n; W)2ZeH*
} 5Cl;h^R|m
ef]60OtP
b0[H{q-z{X
} >?ckBU9
eG%Q 3h
*"sDsXo- I
/* G$CI~0Se:
**SiteInfoBean.java FoGSCg%
*/ XXC(R
package NetFox; *!L it:H
99?: 9g
R2dCp|6A
public class SiteInfoBean { <9aa@c57
q|kkdK|N/Y
);*#s~R
private String sSiteURL; //Site's URL NZt 8L?
private String sFilePath; //Saved File's Path ]VHO'z\m
private String sFileName; //Saved File's Name S01Bc
private int nSplitter; //Count of Splited Downloading File L=<{tzTc
Un{9reX5
^26}8vt
public SiteInfoBean() "yc@_+"\+
{//nSplitter的缺省值为5 Ap9 %5:]
//default value of nSplitter is 5 j$}W%ibj
this("","","",5); p|VgtQ/)%
} 1|3{.Ed
aDVBi: _
^fT?(y_=e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cA25FD
{ _U`1BmTC2
sSiteURL= sURL; 46M?Gfd,X
sFilePath = sPath; W5zlU2
sFileName = sName; 7Un5Y[FZo
this.nSplitter = nSpiltter; Ah1fcXED
,-_\Y hY>
h-=lZ~W~
} (}&O)3)
6@cT;=W;xj
2^T`> ?{X
public String getSSiteURL() 0ZjinWkR[
{ _Sn7z?
return sSiteURL; %TA@-tK=
} ^V;2v? O
5_= HtM[v]
3ew`e"s
public void setSSiteURL(String value) 9ld'SB:#
{ iK <vr
sSiteURL = value; I,wgu:}P#
} >Mc,c(CvU
sU 5/c|&
= ,^eQZR:
public String getSFilePath() L[cl$pYV
{ 2'5%EQW;0y
return sFilePath; 3F|#nq
} k\`~v$R3
nK;c@!~pS
6;vfl*
public void setSFilePath(String value) \oc*
{ #JIh-h@
sFilePath = value; "0#d F:qt
} O6Jn$'os1#
si.w1
y:+4-1
public String getSFileName() 'o.A8su,
{ |Wzdu2T
return sFileName; tNbZ{=I>
} %`1p8>n
M5>cYVG
BT8L'qEj
public void setSFileName(String value) 3T7,Y(<V
{ YdNmnB%J
sFileName = value; 7lYiufg
} jizp\%W+
`X ;2lgL
POtwT">z
public int getNSplitter() xgV(0H}Mf
{ ,/bv3pE
return nSplitter; /a:sWmxMT
} Nn]|#lLP
L?slIGp%-
1 /dy@'
public void setNSplitter(int nCount) u>W:SM
{ Iurb?
nSplitter = nCount; lZ![?t}2`
} ;+-M+9"?O
} krI@N}OU
Bc^MZ~+ip
>azTAX6L3
/* 0v/}W(
**Utility.java 12JmSvD
*/ "cVJqW
package NetFox; ;H;c Sn5uL
Kk?C
x'IYWo ]
public class Utility { +M^+qt;]V
v@^P4cu;
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public Utility() -0o1iU7
{ _)U[c;^6
O<KOsu1WW
f;7I{Z\<
} ljw(cUM
2LqJ.HH
//线程睡眠 ?wpS
public static void sleep(int nSecond) @G&2Tbj[`
{ pDloew
try{ `BOG e;pl
Thread.sleep(nSecond); 9nrmz>es|-
} nB .?=eUa
catch(Exception e) 4u.Fy<+@4M
{ b|'{f?
e.printStackTrace (); LI`H,2Km
} h.%)RW?
} e#/SFI0m
cFF'ygJ/
//日志 {/E_l
public static void log(String sMsg) {I:nza
{ |Y")$pjz
System.err.println(sMsg); t<DZW#
} RP1sQ6$
BdQ/kXZu+
3UX/
public static void log(int sMsg) lc8zF5
{ Fk*C8
System.err.println(sMsg); r;C BA'Z
} _Q=h3(ZI
} 7(W"NF{r
f(Uo?_as
u P&<
/* G%#M17
**TestMethod.java %%h0 H[5*
*/ "eb+O
package NetFox; T_NN.Ol
W0qn$H
PC55A1(T
public class TestMethod { P3op1/Np
sG K7Uy
.wvgHi
public TestMethod() RJ0:O
{ ///xx/weblogic60b2_win.exe xwjiNJ Gj
try{ dc=~EG-_rM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FNy-&{P2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t*dd/a
SiteFileFetch fileFetch = new SiteFileFetch(bean); E~K5n2CI
fileFetch.start(); 9>7w1G#
} 9JBVG~m+
catch(Exception e){e.printStackTrace ();} \F5d p
&++tp5
Q35jJQ$<`
} %RD%AliO}K
?j|i|WUD
GX,)~Syw*
public static void main(String[] args) ~;D5j) 9I
{ }]!?t~5*
new TestMethod(); =Yt)b/0b9
} g7@.Fa.u'!
} qku}cWD9/_
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