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<l1s
} y{N9.H2
for(int i=0;i<nEndPos.length-1;i++) ,y>Na{@Y
{ (X9V-4
nEndPos = nStartPos[i+1]; w9FI*30
} UdGoPzN
nEndPos[nEndPos.length-1] = nFileLength; t'J fiGM
} >g[W@FhT'k
} "Wm~\)t(
A=$oYBB
W)#`4a^xj7
//启动子线程 5c"kLq6r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E;qwoTmul
for(int i=0;i<nStartPos.length;i++) 1bBK1Uw
{ qEAF!iB]L
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5-OvPTY`M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HZ}*o%O
nStartPos,nEndPos,i); gY9"!IVe+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l;.BlHyu
fileSplitterFetch.start(); /K^cU;E,
} (Y>MsqwWfC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xR:h^S^W ~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ueR42J%s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~K9U0ypH
nEndPos = " + nFileLength); `T70FsSJ
// fileSplitterFetch[nPos.length-1].start(); TI>yi ^}
'!R,)5l0h
{9Y'v
//等待子线程结束 Al|7Y/
//int count = 0; ,<1*
//是否结束while循环 9zJ`;1
boolean breakWhile = false; >-P0wowL
.N=hA
+HX'AC
while(!bStop) +a/o)C{
{ W(aRO
write_nPos(); ))`Zv=y"
Utility.sleep(500); 9^u?v`!
breakWhile = true; qN@a<row&~
o!~bR
to3J@:V8e
for(int i=0;i<nStartPos.length;i++) d<'xpdxc
{ eEQ[^i
if(!fileSplitterFetch.bDownOver) ?_aR-[XRg
{ spJ(1F{|V
breakWhile = false; 4*x!B![]y
break; PAHlj,n)
} Gq*)]X{Ua
} F"xO0t
if(breakWhile) B5:g{,C
break; :,m)D775S
`a>vPW
>Mw &Tw}o
//count++; _m],(J=,z
//if(count>4) QIK73^
// siteStop(); hZ<btN.y5
} {yR)}r
\'Ta8
aLi_Hrb9
System.err.println("文件下载结束！"); Z~c'h
} M"^Vf{X^
catch(Exception e){e.printStackTrace ();} 5vft}f
} @@83PJFid
_wNPA1q0J
.KucjRI
//获得文件长度 LUck>l\l
public long getFileSize() wy{>gvqK
{ ,g_onfY
int nFileLength = -1; u!o]Co>
try{ NRisr
URL url = new URL(siteInfoBean.getSSiteURL()); B#"|5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <zuE=0P~%
httpConnection.setRequestProperty("User-Agent","NetFox"); PuCDsojclh
4q13xX
@b\ S.
int responseCode=httpConnection.getResponseCode(); ~AanU1U<
if(responseCode>=400) O}_a3>1DY
{ `t0f L\T
processErrorCode(responseCode); Eqbe$o`dd
return -2; //-2 represent access is error S9R]Zl7{-
} `QdQ?9x{F
-,VhSI
S tnv>
String sHeader; K3:|Tc(
^}Qj}
4iNbK~5j
for(int i=1;;i++) 99"[b
{ hNnX-^J<o
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); pP* ~ =?
//Utility.log(in.readLine()); rA1r#ksQ
sHeader=httpConnection.getHeaderFieldKey(i); u=;nU(]M '
if(sHeader!=null) !?o$-+a|
{ VS|("**
if(sHeader.equals("Content-Length")) X@qk>/
{ 7sc<dM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); R pI<]1
break; U`8|9v
} H [Lt%:r
} ^8NLe9~p3?
else Tz[?gF.Do
break; wB>S\~i
} {^2W>^
} 3z)"U
catch(IOException e){e.printStackTrace ();} x}&a{;
catch(Exception e){e.printStackTrace ();} (X(1kj3
H5rPq_R
Q_aqX(ig
Utility.log(nFileLength); N3gNOq&
*)bd1B#
d"I28PIS"
return nFileLength; 'DzBp
} f[Fgh@4cj
)ojx_3j8
Nxb\[
//保存下载信息（文件指针位置） h zZ-$IX X
private void write_nPos() cc41b*ci$
{ R6q4 ["
try{ iog # ,
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8jggc#.
output.writeInt(nStartPos.length); e(~'pk"mZ
for(int i=0;i<nStartPos.length;i++) :YqQlr\
{ 6!+X.+
// output.writeLong(nPos); kxm:g)`=[
output.writeLong(fileSplitterFetch.nStartPos); wKk 3)@il
output.writeLong(fileSplitterFetch.nEndPos); O:;OR'N9
} ]Y4q'KH
output.close(); l*K I
} G;C8Kde
catch(IOException e){e.printStackTrace ();} ]eYd8s+
catch(Exception e){e.printStackTrace ();} .QXG"R
} u3Usq=Ij{
}UKgF.
6[*;M
//读取保存的下载信息（文件指针位置） ;GE26Ymqly
private void read_nPos() |Bx||=z`
{ eQU-&-wt0
try{ .!yWF?T8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1mHwYT+
int nCount = input.readInt(); ofMu3$Q
nStartPos = new long[nCount]; qGnPnQc
nEndPos = new long[nCount]; By?nd)
for(int i=0;i<nStartPos.length;i++) ]8$#qDS@
{ rH$eB/#F
nStartPos = input.readLong(); =[]x\&@t
nEndPos = input.readLong(); M=5d95*-}
} =U4f}W;
input.close(); Nfv="t9e
} +`;+RDKY*
catch(IOException e){e.printStackTrace ();} WI1T?.Gc
catch(Exception e){e.printStackTrace ();} _1>SG2h{fV
} 5vD3K!\u
xwPI
|7 &|>
private void processErrorCode(int nErrorCode) I&L.;~
{ Dv<wge`
System.err.println("Error Code : " + nErrorCode); 6xH;:B)d
} EXA^!/)
4|[<e-W
TC qkm^xv
//停止文件下载 O(VxMO
public void siteStop() }@Xh xZu
{ gjW\ XY
bStop = true; ,*/Pg52?
for(int i=0;i<nStartPos.length;i++) "\}b!gl$8
fileSplitterFetch.splitterStop(); Q_ctX|.
a9[mZVMgUK
8h2D+1,PZC
} OmB TA=E<
} ,H>W:O
//负责部分文件的抓取 Z6 ;Wd_
**FileSplitterFetch.java O\6vVM[
*/ bqSMDK
package NetFox; -i#J[>=w{C
}@d>,1DU
s(teQ\
import java.io.*; .iFViVZC
import java.net.*; }N?g|
^^%JoQ.
~?gzq~~t
public class FileSplitterFetch extends Thread { Hi^35
>K\3*]>J3
@B?FE\
String sURL; //File URL OY:u',T
long nStartPos; //File Snippet Start Position [w!C*_V 9
long nEndPos; //File Snippet End Position G\R*#4cF
int nThreadID; //Thread's ID T/ik/lFI
boolean bDownOver = false; //Downing is over w&%9IJ
boolean bStop = false; //Stop identical sa*g
FileAccessI fileAccessI = null; //File Access interface gNqAj# m
>?z:2@Q)B
H nK!aa
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :vpl+)n
{ xA92C
this.sURL = sURL; H( vx/q
this.nStartPos = nStart; C,fY.CeI
this.nEndPos = nEnd; *ot>WVB
nThreadID = id; FH.f- ZU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6D|p Qs
} CphFv!k'Z
p!_[qs
Nb0Ik/:<
public void run() 'r\ 4}Ik
{ uQnT[\k?
while(nStartPos < nEndPos && !bStop) 9UV9h_.x
{ 6hO-H&r++
z`4c 4h]I
eIH$"f;L
try{ dN< ,%}R
URL url = new URL(sURL); >p0KFU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t8P PE
httpConnection.setRequestProperty("User-Agent","NetFox"); _g~2R#2Q
String sProperty = "bytes="+nStartPos+"-"; :|rPT)yT]
httpConnection.setRequestProperty("RANGE",sProperty); )n>+m|IqY(
Utility.log(sProperty); YlTaN,?j
7\Co`J>p2
,[* ;UR
InputStream input = httpConnection.getInputStream(); Jd_;@(Eg=
//logResponseHead(httpConnection); ,!Q]q^{C:W
d`mD!)j
)hBE11,PB
byte[] b = new byte[1024]; cLG6(<L
int nRead; c+g@Z"es
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -}P7$|O&
{ S(
nStartPos += fileAccessI.write(b,0,nRead); {]^O:i"
//if(nThreadID == 1) 3#c3IZ-;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DN_W.o
} &l m#
zU&L.+
.XS9,/S
Utility.log("Thread " + nThreadID + " is over!"); >&Y-u%}U
bDownOver = true; _[t8rl
//nPos = fileAccessI.write (b,0,nRead); dEp7{jY1O
} ?s2^zT
catch(Exception e){e.printStackTrace ();} du_4eB
} /&^W#U$4
} MjD75hIZ
qtMD CXZ^n
PyBD
//打印回应的头信息 hr/o<#OW
public void logResponseHead(HttpURLConnection con) r|eZv<6
{ @kxel`,$e
for(int i=1;;i++) ,eRQu.
{ nL-K)G,
String header=con.getHeaderFieldKey(i); #+k*1Jg
if(header!=null) QI_4*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z"y=sDO{
Utility.log(header+" : "+con.getHeaderField(header)); -1u9t4+`
else }Wh6zT)
break; &%mXYj3y5
} Pw[g
} />44]A<
4a''Mi`u
m@Rtlb
public void splitterStop() 'xE _Cj
{ 4(8xjL:
bStop = true; UbamB+QT
} :O= \<t
:j^FJ@2_
U;q];e:,=}
} {d<;BLA
E3aDDFDH
#oni:]E!m
/* nNt1C
**FileAccess.java ])}(k
*//文件访问(定位，写) -E4XIn
package NetFox; '#/G,%m<!i
import java.io.*; T0zn,ej
%w7pkh,
BV#78,8(
public class FileAccessI implements Serializable{ cLVeT
-E"GX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Yz$3;
RandomAccessFile oSavedFile; H<EQu|f&x
long nPos; kOo~%kcQ'
{gbn/{
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public FileAccessI() throws IOException jhbonuV_
{ &0zT I?c
this("",0); 6GPp>X
} M-V&X&?j
uvP2Wgt
YuZ"s55zU{
public FileAccessI(String sName,long nPos) throws IOException RPd}Wf
{ A+J*e
oSavedFile = new RandomAccessFile(sName,"rw"); Ig]iT
this.nPos = nPos; `K~AhlJUQ
oSavedFile.seek(nPos); ^sN (
} 4lhw3,5
%1}K""/
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public synchronized int write(byte[] b,int nStart,int nLen) 4SPy28<f
{ h.O$]:N
int n = -1; =0uAE7q(9
try{ !$N<ds.
oSavedFile.write(b,nStart,nLen); EnOU?D
n = nLen; e@:sR
} _4^R9Bt
catch(IOException e) EBz}|GY;
{ [(1c<b2r
e.printStackTrace (); 9z)5Mdf1j
} w?kJ+lmOQy
dT,o=8fg
"BX!
return n; [kE."#
} 7i&:DePM'q
T^J>ZDA
0d8%T<=J
} GFr|E8
u#}[ZoI
.9Y)AtJTS
/* "Ph^BUAb
**SiteInfoBean.java o sKKt?^?
*/ 6G=j6gK%P
package NetFox; ?-^~f
4Y[1aQ(%
0}_[DAd6
public class SiteInfoBean { {e|[%reSkg
yj^+G
Q7W>qe%4
private String sSiteURL; //Site's URL ai0XL}!+
private String sFilePath; //Saved File's Path V+O"j^Z_J
private String sFileName; //Saved File's Name D_vbSF)
private int nSplitter; //Count of Splited Downloading File LD!Q8"
\L"kV!>
@')[FEdW
public SiteInfoBean() K4kMM*D
{//nSplitter的缺省值为5 cTG|fdgMW
//default value of nSplitter is 5 eUg~)m5G
this("","","",5); =ZqT3_
} %n*-VAfE\
K5lmVF\$P
c"[cNZo
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x)@G;nZ
{ "s{5O>
sSiteURL= sURL; P'_H/r/#
sFilePath = sPath; N0r16# -g
sFileName = sName; @Z12CrJ
this.nSplitter = nSpiltter; !jTcsN%
fZoHf\B]{
]UmFhBR-
} _fKou2$yz
`E>1>'
% yw?s0
public String getSSiteURL() B8}Nvz /
{ h D/*h*}T>
return sSiteURL; ynQ: >tw
} 3qf Ym}d
aJ>65RJ^=
NGbG4-w-
public void setSSiteURL(String value) ojanBg
{ 2%_vXo=I
sSiteURL = value; ;'cN<x)%|
} Hhcpp7cr'
B&n<M]7
A|<jX}
public String getSFilePath() vwxXgk
{ N$U$5;r~`
return sFilePath; )!P)U(*v
} Tu).K.p:
=ACVE;L?
_I:/ZF5
public void setSFilePath(String value) =\H!GT
{ Gz,i~XX
sFilePath = value; $\X[@E S0
} -;^j:L{
ww],y@da
ur:3W6ZKl
public String getSFileName() n[lJLm^(_C
{ w5Y04J
return sFileName; 7$CBx/X50)
} .y!<t}
E87Ww,z8
b4[bL2J$h1
public void setSFileName(String value) A#EDkU,
{ @~^5l
sFileName = value; x!5'`A!W%
} r]:(Vk]|F
9\_eK,*B
fF7bBE)L/|
public int getNSplitter() -zOdU}91Ao
{ 9]f!'d!5
return nSplitter; tX_R_]v3
} 0i!uUF
D1zBsi94D
PQ5QA61
public void setNSplitter(int nCount) vq(0OPj8r[
{ c;Pe/d
nSplitter = nCount; ILEz;D{]
} =;Rtdy/Yn%
} <m)$K
K|zZS%?$
;z}i-cNae
/* +B B@OW
**Utility.java ?XrQ53
*/ l;R%= P?'F
package NetFox; 0D\#Pq v
}X)&zenz
,':fu
public class Utility { P5a4ze
xS4w5i2
8m2Tk\;:
public Utility() *|%@6I(
{ =,spvy'"*C
yu!h<nfzA
Ugu[|,
} l{I6&^!KS
#5cEV'm;
//线程睡眠 Cl;oi}L
public static void sleep(int nSecond) Rdvk ml@@
{ iU$] {c2;A
try{ QM5R`i{r
Thread.sleep(nSecond); YVQN&|-
} t<#mP@Mz=N
catch(Exception e) KHe=O1 %QO
{ {> eXR?s/
e.printStackTrace (); -+(jq>t
} Tl(^
} "6MVvpy"
[ey:e6,T9
//日志 nKPYOY8^
public static void log(String sMsg) +giyX7BPJ
{ hn5h\M?
System.err.println(sMsg); Zn&, t &z
} K0-ypU*P
HePUWL'
>80;8\
public static void log(int sMsg) HW3 }uP\c
{ FQu8vwV6>
System.err.println(sMsg); 4 !i$4
} -~s!73pDY
} Rp.Sj{<2
R)_%i<nq\
fol,xMc&
/* tNO-e|~'
**TestMethod.java %`>nS@1zp
*/ F"&~*m^+
package NetFox; d/PiiiFf,
$Z.7zH
'8Q]C*Z
public class TestMethod { 5's87Z;6
$bW3_rl%X
jr)1(**
public TestMethod() ozmrw\_}[
{ ///xx/weblogic60b2_win.exe ?u{~>
try{ *@Lp`thq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pf1BN@ t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U &C!}
SiteFileFetch fileFetch = new SiteFileFetch(bean); VPO N-{=`
fileFetch.start(); C"6?bg5N
} kE:nsXI )
catch(Exception e){e.printStackTrace ();} <Wfx+F
PPb7%2r
D?;"9e%
} ~Mx!^
:}5j##N
(61EDKNd9
public static void main(String[] args) *^g:P^4
{ )Q1"\\2j0
new TestMethod(); #r#1JtT
} HBy[FYa4
} YM1'L\^
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