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)); G)~/$EF,_
} a`/\0~
for(int i=0;i<nEndPos.length-1;i++) >Pa&f20Hp
{ IZ?+c@t
nEndPos = nStartPos[i+1]; j{QzD^t
} miWog8j
nEndPos[nEndPos.length-1] = nFileLength; {vCB$@/o
} ;1x(~pD*o
} 'Lm\ r+$F
W}^X;f
zsM3 [2E*
//启动子线程 D@.+B`bA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;W"=s79
for(int i=0;i<nStartPos.length;i++) z)AZ:^!O
{ LC8&},iu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4WspPHj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1nGpW$Gx
nStartPos,nEndPos,i); 2h=QJgpCG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z'hHXSXM
fileSplitterFetch.start(); !q]@/<=
} {,;R\)8D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2Kg-ZDK8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p;nRxi7'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o'Rr2,lVi
nEndPos = " + nFileLength); {N.JA=
// fileSplitterFetch[nPos.length-1].start(); \3K%>
*z?Vy<u G
P|U9f6^3
//等待子线程结束 `IC2}IiF
//int count = 0; 2Q bCH}
//是否结束while循环 P]h-**O
boolean breakWhile = false; g/3t@7*<
<D}yqq@|
|FED<
while(!bStop) 4eD>DW
{ QYB66g:
write_nPos(); qS|ns'[
Utility.sleep(500); UO~Xzx!e
breakWhile = true; /9QC$Z):<
/&>vhpZ}
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for(int i=0;i<nStartPos.length;i++) 8%\0v?a5
{ p)&Yr
if(!fileSplitterFetch.bDownOver) U7_1R0h
{ gPJZpaS
breakWhile = false; H;DCkVL
break; Al}D~6MD
} A WS[e$Mt2
} nNc>nB1
if(breakWhile) V'iT>
break; Y%zYO
[\BLb8
B!j7vXM2
//count++; #ULjK*)R
//if(count>4) $R&K-;D/8
// siteStop(); EX"o9'
} k`(Cwp{Oc
V'M#."Of/
*!5X!\e_
System.err.println("文件下载结束！"); B'}pZOa[Wb
} n.l7V<1
catch(Exception e){e.printStackTrace ();} G4<M@ET
} `zoC++hx
Z%4w{T+[
Rlwewxmr
//获得文件长度 G2 {R5F !
public long getFileSize() >{1 i8 b@
{ n=iL6Yu(
int nFileLength = -1; =zsA@UM0
try{ EK8rV
URL url = new URL(siteInfoBean.getSSiteURL()); &x.n>O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YQ$Wif:@(n
httpConnection.setRequestProperty("User-Agent","NetFox"); eeM$c`Y<
YiGSFg
LW#$%}
int responseCode=httpConnection.getResponseCode(); A7enC,Ey
if(responseCode>=400) bdYx81
{ Eb~e=){
processErrorCode(responseCode); Rm&4Pku
return -2; //-2 represent access is error hd%O\D?
} cOoF +hz0O
k [eWhdSw
>c30kpGg
String sHeader; pPH"6
'7yVvd
x%J.$o[<_
for(int i=1;;i++) [}Z!hq
{ jccSjGX@w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "lnI@t{o
//Utility.log(in.readLine()); ]w/%>
sHeader=httpConnection.getHeaderFieldKey(i); P.Gmj;
if(sHeader!=null) g;-6Hg'
{ 6` 4,
if(sHeader.equals("Content-Length")) phP%
{ =IEei{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XGcl9FaO}
break; Mh@RO|F
} {^A,){uX]
} S4C4_*~Vd
else njGZ#{"eC
break; \J-}Dp\0b
} ]yV,lp
} Y+Cqc.JBQ
catch(IOException e){e.printStackTrace ();} %pUA$oUt
catch(Exception e){e.printStackTrace ();} z/P^Bx]r
@3_."-d
;y]BXW&l&
Utility.log(nFileLength); =2OLyZDI
)u>/:
Lg2z `uv
return nFileLength; $*qQ/hi
} <!a%GI
_%@ri]u{ov
|y DaFv
//保存下载信息（文件指针位置） EHH+)mlo
private void write_nPos() #v\o@ArX
{ V]W-**j<
try{ l|L ]==M
output = new DataOutputStream(new FileOutputStream(tmpFile)); VpyqVbx1
output.writeInt(nStartPos.length); EXizRL-9o
for(int i=0;i<nStartPos.length;i++) uGY(`
{ *T-v^ndJh
// output.writeLong(nPos); f5P@PG]{
output.writeLong(fileSplitterFetch.nStartPos); 9iM[3uyO
output.writeLong(fileSplitterFetch.nEndPos); jpt-5@5O
} u!TMt8+c
output.close(); P*g:rg
} cNG`-+U'
catch(IOException e){e.printStackTrace ();} /|WBk}
catch(Exception e){e.printStackTrace ();} ,T0q.!d
} [WUd9fUL
z+{Q(8'b]
v<:/u(i
//读取保存的下载信息（文件指针位置） %ou@Y`
private void read_nPos() <G /a-Z
{ cIQe^C
try{ Rc#c^F<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?XnKKw\
int nCount = input.readInt(); #<81`%
nStartPos = new long[nCount]; LPS]TG\
nEndPos = new long[nCount]; 2|JtRE+
for(int i=0;i<nStartPos.length;i++) OR<%h/ \f
{ .9$ 7 +
nStartPos = input.readLong(); "W@>lf?"
nEndPos = input.readLong(); rtT*2k*
} +?ilTU
input.close(); c^8csQ fG
} {O5(O oDa
catch(IOException e){e.printStackTrace ();} c;doxNd6
catch(Exception e){e.printStackTrace ();} R=<uf:ca
} G~{#%i
SGUZ'}
y1t,i. [
private void processErrorCode(int nErrorCode) bq"dKN`
{ 2+}hsGnp
System.err.println("Error Code : " + nErrorCode); IP+.L]S
} zc&i 4K
u$ a7
';KZ.D
//停止文件下载 !Nx'4N`&l
public void siteStop() I`S?2i2H
{ N'=b8J-fF
bStop = true; R:, |xz
for(int i=0;i<nStartPos.length;i++) =S<E[D{V`
fileSplitterFetch.splitterStop(); ;3 /*Z5p
w3K>IDWI7
+OfHa\Nz
} #OVS]Asn}
} x]pZcx9
//负责部分文件的抓取 [KNA5(Y0
**FileSplitterFetch.java SxW.dT8{
*/ ;, ^AR{+x
package NetFox; IZ&FNOSZ+4
v 0D@`C
E#(dri*#t
import java.io.*; U@"f(YL+"
import java.net.*; #iAw/a0&
2}kJN8\F
#8i9@w
public class FileSplitterFetch extends Thread { )5Ofr-Y
_g%h:G&^
hZUnNQ
String sURL; //File URL :nn(Ndlz9
long nStartPos; //File Snippet Start Position p.x!dt\1kC
long nEndPos; //File Snippet End Position uTRFeO>
int nThreadID; //Thread's ID gF~#M1!!
boolean bDownOver = false; //Downing is over vhL/L?NB$
boolean bStop = false; //Stop identical 7qEc9S@
FileAccessI fileAccessI = null; //File Access interface 04@?Jb1*
f1 Zj:3e
`+5,=S
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException VZCCMh-
{ K yDPD'
this.sURL = sURL; yN9setw*,M
this.nStartPos = nStart; a"whg~
this.nEndPos = nEnd; e8VtKVcY
nThreadID = id; aSQvtv)91
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |s, Add:S
} {:ZsUnzm
FSA"U9 w<
ySNXjH Q=
public void run() cp L'
{ ]Aa.=
while(nStartPos < nEndPos && !bStop) w?"s6L3
{ <gjA(xT5
v|GDPq
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try{ 4j}uVGi{e
URL url = new URL(sURL); G&dz<f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mE"},ksg
httpConnection.setRequestProperty("User-Agent","NetFox"); |\J! x|xy
String sProperty = "bytes="+nStartPos+"-"; xv~EwT)
httpConnection.setRequestProperty("RANGE",sProperty); z1m$8-4
Utility.log(sProperty); -"/l)1ox,
t+2,;G
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InputStream input = httpConnection.getInputStream(); <XH,kI(%
//logResponseHead(httpConnection); <a)L5<#
q*d@5
`m=u2kxY
byte[] b = new byte[1024]; 'h{| ]
int nRead; @%4tWE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,]Q i/m
{ 2PG= T/
nStartPos += fileAccessI.write(b,0,nRead); Z=[?Tf
//if(nThreadID == 1) xOBzT&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y!fgc<]'&
} xL}~R7
A&7~]BR\
+hzS'z)n&
Utility.log("Thread " + nThreadID + " is over!"); %TS8 9/
bDownOver = true; GCv*a[8?n
//nPos = fileAccessI.write (b,0,nRead); EbMG9
} Erq%Ck(
catch(Exception e){e.printStackTrace ();} *;Gnod<
} d <Rv~F@
} GOj<>h}r
Z Ne(sg~G
=SpD6 9-H
//打印回应的头信息 G ,?l o=m
public void logResponseHead(HttpURLConnection con) ZmzYJ$:6
{ B|.8+Q
for(int i=1;;i++) XWYLa8Ef
{ _l$X![@6=
String header=con.getHeaderFieldKey(i); ^eY% T5K
if(header!=null) ;/)u/[KAv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Mt
Utility.log(header+" : "+con.getHeaderField(header)); y3Lq"?h
else @;g|styh^
break; 3FhkK/@
} 0mYKzJi
} jR@J1IR<
iYBp"+#2
CT#u+]T
public void splitterStop() P=PVOt@ b
{ VY_<c98v
bStop = true; 82A[[^`
} RZ GD5`n
XpoEZ|0
;.#l[
} ^UiSezcI
U!Eo*?LU$
0\}%~e
/* ODE^;:z !
**FileAccess.java y-k]Tr
*//文件访问(定位，写) 1zlBkK
package NetFox; Ph/!a6y
import java.io.*; U[WR?J4~LX
bbAJ5EqL
j hrpS
public class FileAccessI implements Serializable{ 0="U'|J_
cH{[\F"Eb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wxIWh>pZa
RandomAccessFile oSavedFile; C .{`-RO
long nPos; $R_RKyXzo
s7G!4en
5.X`[/]<r
public FileAccessI() throws IOException z2Kvp"-}
{ 0VwmV_6'<W
this("",0); d|RDx;rl8
} 7@l.ZECJ1
!a<}Mpeg
0w<G)p~%n
public FileAccessI(String sName,long nPos) throws IOException 9#D?wR#J=
{ oH]"F
oSavedFile = new RandomAccessFile(sName,"rw"); 3*;S%1C^
this.nPos = nPos; |8s45g>
oSavedFile.seek(nPos); f<}>*xH/k
} Y.}8lh eH
q:X&)f
LG>lj$hO
public synchronized int write(byte[] b,int nStart,int nLen) -naoM
{ 'Nn>W5#))
int n = -1; PAHkF&
try{ YDoVm?
oSavedFile.write(b,nStart,nLen); 0DgEOW9H
n = nLen; N\Li/
} 2/M:KR
catch(IOException e) @>4=}z_e
{ 8@Hl0{q
e.printStackTrace (); Q]"u?Q]
} h Lv_ER?
Gp5[H}8K
iQj2aK Gs
return n; [|E|(@J
} =!Ce#p?h,
dPO|x+N,
`ot<BwxJ
} Md(h-wYr
y`Km96Ui
kjOPsz*0
/* p5PTuJ>q
**SiteInfoBean.java $9m>(b/;n
*/ |JRaskd
package NetFox; .W1i3Z6g
( V^C7ix:
b am*&E%0K
public class SiteInfoBean { Z9vJF.clO
[S#QGB19
>UDb:N[
private String sSiteURL; //Site's URL R<AT}!mkR
private String sFilePath; //Saved File's Path 6i.!C5YX]
private String sFileName; //Saved File's Name Y[WL}:"93
private int nSplitter; //Count of Splited Downloading File UYW{AG2C
,s.{R
g?=|kp
public SiteInfoBean() %}x$YDO
{//nSplitter的缺省值为5 =V(|3?N
//default value of nSplitter is 5 Wp0L!X=0
this("","","",5); >;M?f!
} ^ua8Ya
IQya{e
@h$4Mt7N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F4`5z)<*
{ ]f<H?
sSiteURL= sURL; %tC3@S
sFilePath = sPath; ;;;{<GEQ
sFileName = sName; -D-]tL6w
this.nSplitter = nSpiltter; UxS@]YC
5^+QTQ
(iO8[
} s_`=ugue
k5ZkD+0Jo
`SH#t3 5,
public String getSSiteURL() oM4Q_An
{ >L{s[pLJ
return sSiteURL; o6LZ05Z-&
} 8R;A5o,
Mu?hB{o1
t3b64J[A{
public void setSSiteURL(String value) UI}df<Ge
{ ~|t7
sSiteURL = value; }W)c-91
} ]x<`(
JZM:R
pz]T9ol~
public String getSFilePath() +#IsRiH%>
{ V(A p|I:G
return sFilePath; d|?'yX
} kICZc{} `
Ebk_(Py\
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public void setSFilePath(String value) P.Uz[_&l6
{ gk.c"$2
sFilePath = value; \Rff3$
} 0>KW94
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WP b4L9<
public String getSFileName() K9 tuiD+j
{ EX.`6,:+2
return sFileName; fZ)M Dq
} se:lKZZ]
vsU1Lzna6@
v2tKk^6`(i
public void setSFileName(String value) wf[B-2q)
{ 8H})Dq%d7
sFileName = value; sVjM^y24
} ,b/qcu_|-
O^W.5SaR
z%cpV{Nu
public int getNSplitter() RV2s@<0p
{ vUa&9Y
return nSplitter; 5`?'}_[Yj
} 6)B6c. 5o
F7r!zKXZ
0M^v%22
public void setNSplitter(int nCount) xct{Tv[FO
{ y:>'1"2`
nSplitter = nCount; @! gJOy
} Hi{1C"%
} /y.+N`_
rnV\O L
}#3'72
/* <E`Ygac
**Utility.java ,( ?q
*/ I2R" Y<
package NetFox; nM?mdb
HpD<NVu
A_mVe\(*M
public class Utility { $aFCe}3b<
~)kOOoH
r- :u*
public Utility() 8LMO2Wyq
{ uIO<6p)
}{(dG7G+
1oSrhUTy
} $%3"@$
? !dy
//线程睡眠 tf5h/:
public static void sleep(int nSecond) {M.OOEcIp
{ rrSsQq
try{ (<"uV%1
Thread.sleep(nSecond); >5aZ?#TS1
} uV@#;c4
catch(Exception e) "Y> #=>8
{ :E>"z6H
e.printStackTrace (); HL^+:`,
} tlnU2TT_f
} ?C[W~m P
g{_wMf
//日志 ]&dU%9S
public static void log(String sMsg) (zO)J`z>
{ ~KW|<n4m
System.err.println(sMsg); v%=@_`Ht
} 0^L>J"o
007(k"=oV
^J TrytIB
public static void log(int sMsg) [K\Vc9
{ B3j
System.err.println(sMsg); (rHS2SA\5
} Bv)^GU&
} )5479Eb_
E,/<;
- DO
/* Ob+Rnfx37
**TestMethod.java M$9?{8m
*/ m~#f L
package NetFox; (2oP=9m
Ju"*;/
%l#i9$s
public class TestMethod { T;f`ND2fY
94>EA/+Ek
i1OF@~?
public TestMethod() E=-ed9({:
{ ///xx/weblogic60b2_win.exe vH^6O:V
try{ 'K L"i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V?.')?'V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =41g9UQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); UcHe"mn
fileFetch.start(); .}wVM`81z
} q,8TOn
catch(Exception e){e.printStackTrace ();} oV(|51(f
X4c|*U=4
EU@ BNja
} e#+u8LrN
'\MYC8"
sUCI+)cM3
public static void main(String[] args) >;$C@
{ hLqRF4>L
new TestMethod(); co93}A,k
} &tAhRMa
} <K(qv^C
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