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)); FTr'I82m(
} `-JVz{z
for(int i=0;i<nEndPos.length-1;i++) UfIr"bU6
{ \a4X},h\
nEndPos = nStartPos[i+1]; $;&l{=e2)
} D|amKW7
nEndPos[nEndPos.length-1] = nFileLength; z9!OzGtIR
} /ykc`E?f
} -u7NBtgUh
qRR%aJ/
dBwoAq`'
//启动子线程 +v~x_E5FP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bU[_YuJbM
for(int i=0;i<nStartPos.length;i++) d}%-vm} 0
{ ftKL#9,s(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Dlpmm2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G3 |x%/Fbp
nStartPos,nEndPos,i); ,!,tU7-H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `kE7PXqa
fileSplitterFetch.start(); w+r).PS}C
} KnKf8c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bT6VxbNS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u0]u"T&N!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R={#V8D~
nEndPos = " + nFileLength); *VmX.
// fileSplitterFetch[nPos.length-1].start(); PD^G$LT
IMncl=1
4AKr.a0q
//等待子线程结束 9 *uK]/c
//int count = 0; 93Zij<bH?e
//是否结束while循环 mP=[h |a$r
boolean breakWhile = false; xXc>YTK'
rd<43
ZyDNtX%
while(!bStop) o='A1P
{ Faa>bc~E
write_nPos(); e(N},s:_
Utility.sleep(500); OR*JWW[]
breakWhile = true; vcsSi%M\U
hv?T}E
'6})L
for(int i=0;i<nStartPos.length;i++) YU"/p|!1
{ -8Hc M\b
if(!fileSplitterFetch.bDownOver) a5R. \a<q
{ Y9|!=T%
breakWhile = false; l S3LX
break; "\O7_od-
} BWvM~no
} z HvE_-
if(breakWhile) w/O'&],x
break; ;[UI]?A%
j7MUA#6$
$,J}w%A
//count++; |(ab0b #
//if(count>4) [k>{q+MWK
// siteStop(); H8I)D& cw
} ?ueL'4Mm
j6EF0/_|e
*;9H\%
System.err.println("文件下载结束！"); [5p3:D
} ;y. ;U#O
catch(Exception e){e.printStackTrace ();} l?2
} pi~5}bF!a
P8}IDQ9
Z{BK@Q4z
//获得文件长度 gm2|`^Xq$
public long getFileSize() ]7cciob
{ = g &
int nFileLength = -1; Pg8boN]}
try{ O|+ZEBP
URL url = new URL(siteInfoBean.getSSiteURL()); -&`_bf%M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )I3E
httpConnection.setRequestProperty("User-Agent","NetFox"); /KWdIP#
?wPTe^Qtv
i8k} B o
int responseCode=httpConnection.getResponseCode(); u-|%K.A
if(responseCode>=400) gk6R#
{ n]Yz<#
processErrorCode(responseCode); i_Q1\_m!
return -2; //-2 represent access is error ~EY)c~H
} &WBpd}|+Y
)L6 it
S$hxR
String sHeader; 1Z)P.9c
#*.4Jv<R
lqv}~MC
for(int i=1;;i++) Q2Ey RFT
{ ?OF$J|h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); eA2*}"W
//Utility.log(in.readLine()); 9)]`le
sHeader=httpConnection.getHeaderFieldKey(i); eA(\#+)X `
if(sHeader!=null) Ncbe{}<md
{ O0z-jZ,])
if(sHeader.equals("Content-Length")) NR(rr.
{ USN'-Ah
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @xBb|/I
break; #&IrCq+
} NAE|iyw
} XchD3p+uB
else D*~Q;q>
break; Zy3F%]V0
} `Zo5!"'
} jrN 5l1np
catch(IOException e){e.printStackTrace ();} #e-7LmO~
catch(Exception e){e.printStackTrace ();} c^1JSGv
OfBWf6b
aC1 xt(
Utility.log(nFileLength); 89D`!`Ah]
3{co.+
rwUhNth-Qh
return nFileLength; ^0>^5l'n
} T+P{,,a/]
uGXvP(Pg'
SGZYDxFC@
//保存下载信息（文件指针位置） EJC}"%h
private void write_nPos() um]*nXIr
{ rjcH[U(
try{ XS@iu,uO
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?:60lCqj
output.writeInt(nStartPos.length); 2BOH8Mp9
for(int i=0;i<nStartPos.length;i++) gsQn@(;
{ [7DU0Xg7
// output.writeLong(nPos); W3\+51P
output.writeLong(fileSplitterFetch.nStartPos); A ;`[va
output.writeLong(fileSplitterFetch.nEndPos); M_E$w$l2<
} XU}i<5
output.close(); \)\n5F:Zu
} !vl1#@
catch(IOException e){e.printStackTrace ();} bupW*fD:
catch(Exception e){e.printStackTrace ();} sOWP0xY
} wd|^m%
5?>Q[a.Ne
"N%W5[C{
//读取保存的下载信息（文件指针位置） j^8Hjg
private void read_nPos() 7SkW!5
{ N/{=j
try{ MJe/ \
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cqh1,h$sG
int nCount = input.readInt(); =u9e5n
nStartPos = new long[nCount]; U/q"F<?.c
nEndPos = new long[nCount]; $?kTS1I(
for(int i=0;i<nStartPos.length;i++) P!9-!+F"
{ Ve[Kv07
nStartPos = input.readLong(); :X9;KoJl-V
nEndPos = input.readLong(); GPs4:CIgG
} Rb b[N#p5
input.close(); u5qaLHoEP
} su\Lxv
catch(IOException e){e.printStackTrace ();} Aj\m57e,6
catch(Exception e){e.printStackTrace ();} QxEmuiN
} O&.gc p!
uKIR$n"
iN u k5
private void processErrorCode(int nErrorCode) <4?(|Vh[m]
{ ;erxB6*
System.err.println("Error Code : " + nErrorCode); yP@#1KLa+
} YL;*%XmAG
=}0>S3a.7
= "Lb5!
//停止文件下载 Jn?ZJZ
public void siteStop() ezJ^ r,D|
{ }236{)DuN
bStop = true; Pa\yp?({q
for(int i=0;i<nStartPos.length;i++) G7-.d/8|^
fileSplitterFetch.splitterStop(); W}(xE?9&
xWQQX
M _Lj5`
} W7V#G(cpU
} sDHFZ:W
//负责部分文件的抓取 `kOp9(Q{
**FileSplitterFetch.java i}:^<jDv?
*/ ,+n{xI2
package NetFox; 5iItgVTW
= p2AK\
C0e oV}
import java.io.*; :VRQd}$Pi
import java.net.*; Q;2kbVWY
J0@#xw=+
,tFLx#e#
public class FileSplitterFetch extends Thread { GV)DLHiyxX
N':d T
c&L|e$C]
String sURL; //File URL >?X(,c
long nStartPos; //File Snippet Start Position b Oh[(O!
long nEndPos; //File Snippet End Position U3>ES"N
int nThreadID; //Thread's ID d{'u97GDc
boolean bDownOver = false; //Downing is over gWjz3ob
boolean bStop = false; //Stop identical 5Obv/C
FileAccessI fileAccessI = null; //File Access interface \xZ6+xZd1
t_X=x`f
F,GG>(6c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QbAEWm
{ UD]RWN
this.sURL = sURL; h5H#xoCXp
this.nStartPos = nStart; 98l-
this.nEndPos = nEnd; 2;ogkPv'
nThreadID = id; W2,Uw1\:1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +^aM(4K\
} @F5QgO J&r
?0+J"FH# W
?B4X&xf.D
public void run() Fmrl*tr
{ H]f8W]"c[
while(nStartPos < nEndPos && !bStop) M059"X="
{ -S}^b6WL
pe`&zI_`?
^w}BXVn
try{ 4L6'4t"s
URL url = new URL(sURL); 9fqCE619a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z"@UNypc,
httpConnection.setRequestProperty("User-Agent","NetFox"); 8nRxx`U\q
String sProperty = "bytes="+nStartPos+"-"; r?n3v[B
httpConnection.setRequestProperty("RANGE",sProperty); *3Ci4\Ew
Utility.log(sProperty); @z.HyQ_v
0R?LWm j
,#=;V"~9
InputStream input = httpConnection.getInputStream(); 2`/p V0
//logResponseHead(httpConnection); EtvYIfemr
^pa -2Ao6
K06&.>v_
byte[] b = new byte[1024]; Q|HOy8O}Z
int nRead; &f>1/"lnd\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) KA0_uty/T
{ uQg&A`4
nStartPos += fileAccessI.write(b,0,nRead); cLnvb!g'#
//if(nThreadID == 1) h)C`w'L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OOX}S1lA
} Q pbzx/2h
Wp$'#HhB
3HmJixy
Utility.log("Thread " + nThreadID + " is over!"); SE!0f&
bDownOver = true; *e-+~/9~
//nPos = fileAccessI.write (b,0,nRead); VbzW4J_
} Jyu*{
catch(Exception e){e.printStackTrace ();} UzmD2AsO"
} pSJc.j
} a<`s'N1G
k39;7J
&!FWo@
//打印回应的头信息 ?wS/KEl=O
public void logResponseHead(HttpURLConnection con) q]o^Y
{ ( u}tUv3
for(int i=1;;i++) tqe8:\1yK
{ a)Ca:p
String header=con.getHeaderFieldKey(i); B mxBbg
if(header!=null) APucA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yY42+%P
Utility.log(header+" : "+con.getHeaderField(header)); |nj,]pA
else h/n&&J
break; >)PcK
} 7vs>PV
} dg]: JU
rYMHc@a9(
+gOv5Eno-
public void splitterStop() VlQaT7Q
{ n~NOqvT <
bStop = true; a5xp[TlXn.
} `[Xff24(eb
A5> ,e|
/"<o""<]
} zcNv T
ta 66AEc9
PxHHh{y%c
/* Os-sYaW
**FileAccess.java H|0GRjC
*//文件访问(定位，写) nE3'm[)
package NetFox; S20L@e"U
import java.io.*; @eGJ_J
2U;ImC1g
4U;6 2 jq
public class FileAccessI implements Serializable{ |H'4];>R?
)tyhf(p6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wd`lN,WiW
RandomAccessFile oSavedFile; !4f0VQI
long nPos; 3o=K?eOdg
pkL&j<{
Yw\PmRL"p
public FileAccessI() throws IOException fc#zhp5bX
{ &u'$q
this("",0); f6h!wx
} [nam H a
ZsPT!l,
t:G67^<3
public FileAccessI(String sName,long nPos) throws IOException C"P40VQoo
{ BM&.Tw|x
oSavedFile = new RandomAccessFile(sName,"rw"); @;we4G5
this.nPos = nPos; Sp=6%3fZ]m
oSavedFile.seek(nPos); [l2ds:
} &O5W
@sAT#[j
crt )}L8-
public synchronized int write(byte[] b,int nStart,int nLen) Ok=RhoZZ
{ CN$wlhs
int n = -1; ljij/C=
try{ DhwFD8tT
oSavedFile.write(b,nStart,nLen); U]Vu8$W
n = nLen; <y}`PmIM I
} Qf|=xV,F
catch(IOException e) /{';\?w
{ Tc DkKa
e.printStackTrace (); 8_S<zE`Ha
} 0OndSa,
<4{,u1!t
L"akV,w4p
return n; 2?9SM@nAY
} EVW{!\8[
JEK6Ms;)A
w}<CH3cx
} ^f-?xXPx
#mNM5(o
i%8I (F
/* w>:~Ev]
**SiteInfoBean.java k#I4^
*/ S&A, Q'
package NetFox; Xq9n-;%zL
4{h?!Z*
El~x$X*
public class SiteInfoBean { F8J;L](Dq
8v},&rhPQq
\o-Q9V
private String sSiteURL; //Site's URL 1Y"[Qs]"mU
private String sFilePath; //Saved File's Path a3wTcp "r
private String sFileName; //Saved File's Name ^gwVh~j
private int nSplitter; //Count of Splited Downloading File ]}_@!F)
J?WT
Z^w}: {
public SiteInfoBean() Rl7V~dUY
{//nSplitter的缺省值为5 +)#d+@-
//default value of nSplitter is 5 P~V0<$C
this("","","",5); m/)Wn
} }vRs n-E@
>bia FK>t
xHv<pza:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .D^=vuxt~
{ 7(m4,l+(
sSiteURL= sURL; Vj7(6'Hg
sFilePath = sPath; dF2 &{D"J
sFileName = sName; ]bG8DEwD
this.nSplitter = nSpiltter; ^FJ=/#@T
;&Q8xC2
P#/k5]g
} ]o<'T.x
}b-"[TDEF
N:j"W,8
public String getSSiteURL() rzH*|B0g
{ 5eI3a!E]O
return sSiteURL; e7f3dqn0
} E?o1&(2p
28u)q2s^W|
M^\#(0^2@
public void setSSiteURL(String value) Vd2bG4*=
{ fZ2>%IxG}
sSiteURL = value; P;D)5yP092
} X'4g\)*
/ c1=`OJ
Fi+v:L|
public String getSFilePath() A2{u("^[6
{ #>+O=YO
return sFilePath; - Dm/7Sxd`
} 7q>WO
HhN;&67~Z
.'md `@t
public void setSFilePath(String value) x:W nF62
{ Bb^CukS:
sFilePath = value; C0o0 l>
} <0OZ9?,dm
F6*n,[5(
yUF<qB
public String getSFileName() -s`/5kD
{ CQf!<
return sFileName; nPp\IE}:
} ^EGe%Fq*x]
P9~7GFas|
=W(mZ#*vdY
public void setSFileName(String value) ^2L\Y2
{ 9Xb,Swo~
sFileName = value; <]6])f,y\
} ,E{z+:Es
RF/I*5
z;6Tp
public int getNSplitter() ?\MvAG7Y
{ xc.(-g[
return nSplitter; V @A+d[
} \2(Uqf#_
nUi 4!|r
5[.Dlpa'7
public void setNSplitter(int nCount) F-?K]t#
{ iUl5yq
nSplitter = nCount; .4c* _$
} YPQ&hEu0
} }D_h*9
~|e?@3_G
RG [*:ReB9
/* \ct)/
**Utility.java @= f2\hU
*/ ~^((tT
package NetFox; m6J7)Wp
7%C6hEP/*W
<aJdm!6
public class Utility { T4,dhS|
0 1U/{D6D
%~`8F\Hiu
public Utility() D_oGhQYY4
{ tsdkpt
cd1M0z
C8qA+dri
} 5)fEs.r0U
<[O8{9j
//线程睡眠 QXZjsa_|
public static void sleep(int nSecond) MP/6AAt7=|
{ T#'+w@Q9{9
try{ \IJ\
Thread.sleep(nSecond); u_[^gS7
} /QDlm>FM4
catch(Exception e) 5$o]D
{ s@^(1g[w`
e.printStackTrace (); f/t1@d!
} 2P9gS[Ub
} &WN#HI."]
lhsd39NM
//日志 WZq0$:I;R
public static void log(String sMsg) ea-NqdGs;m
{ c,%9Fh?(
System.err.println(sMsg); //63?s+
} jE!<]
))"J
Mf)0Y~_:R#
public static void log(int sMsg) 5MsE oLg
{ K7 >Z)21
System.err.println(sMsg); zlC|Spaf
} j0b?dKd
} SE=3`rVJ
j+0=)Q%I=
yi`Z(j;
/* J [}8&sn
**TestMethod.java MNURYA=
*/ k,o|"9H
package NetFox; CAg\-*P|
l]Ozy@ Ib
=KfV;.&
public class TestMethod { m1DzUq;
:A%|'HxH3
G0p|44_~t
public TestMethod() &9bsTm
{ ///xx/weblogic60b2_win.exe k2Yh?OH
try{ k$`~,LJp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A<ca9g3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D<9FSxl6
SiteFileFetch fileFetch = new SiteFileFetch(bean); q]F2bo
fileFetch.start(); T1TKwU8l
} g3~e#vdz
catch(Exception e){e.printStackTrace ();} rZ<n0w
S;DqM;Q
)-$Od2u2c
} 9-)D"ZhLe
ycAQHY~n
]jNv}{
public static void main(String[] args) bDI#'F
{ bqEQP3t^
new TestMethod(); m89-rR:Kc
} P/;sZo
} :wiQ^ea
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