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)); F>n_k
} 8(q8}s$>
for(int i=0;i<nEndPos.length-1;i++) F2<Q~gQ;
{ 3|G~_'`RLt
nEndPos = nStartPos[i+1]; 9<P%?Q
} g2LvojR
nEndPos[nEndPos.length-1] = nFileLength; ;BWWafZ
} }lJ|nl`c
} 7OXRR)]V
=*+f2
8<Yv:8%B6
//启动子线程 > 9z-/e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4PU@W o
for(int i=0;i<nStartPos.length;i++) D0S^Msk9L
{ ~WV1t][
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :AuKQ`c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P&Xy6@%[Z
nStartPos,nEndPos,i); DSp~k)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j 7O!uUQQ
fileSplitterFetch.start(); fffWvf
} 9M|#X1r{%{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -{d(~XIo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f1o^:}5x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 94*MRn1E
nEndPos = " + nFileLength); ) 54cG
// fileSplitterFetch[nPos.length-1].start(); _x!/40^G
/Q#eP m
l 8GAZ*+
//等待子线程结束 KiC,O7&<
//int count = 0; c1*^ \
//是否结束while循环 "8(8]GgYx
boolean breakWhile = false; !>K=@9NC|.
Sv>CVp*
PIQd=%?'
while(!bStop) qla=LS\-A+
{ b1=! "Y@
write_nPos(); E J6|y'
Utility.sleep(500); ,~l4-x.,
breakWhile = true; l}g_<
duCXCX^n T
}J\7IsM&
for(int i=0;i<nStartPos.length;i++) wn<k"6x
{ gMZrtK`<
if(!fileSplitterFetch.bDownOver) %JA^b5''
{ !|ic{1!_
breakWhile = false; 5Go@1X]I
break; B&*`A&^y
} -&v0JvTJ9j
} P{2ED1T\
if(breakWhile) $3970ni,?O
break; !@+4&B=
~_-+Q=3
w0<1=;_%
//count++; =1O;,8`
//if(count>4) ;1TQr3w
// siteStop(); <<YH4}wZ
} 4Xv."L
[,z>msEB.
{;JFoe+
System.err.println("文件下载结束！"); *tDxwD7
} &&96kg3
catch(Exception e){e.printStackTrace ();} '0qKb*
} S^i<_?nwg
v:9Vp{)
MP Q?Q]'
//获得文件长度 LN'})CI8m
public long getFileSize() WO+>W+|N
{ 3|/zlKZz
int nFileLength = -1; }~<9*M-P
try{ nqcD#HUv
URL url = new URL(siteInfoBean.getSSiteURL()); Et)j6xz/F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~}K$z
httpConnection.setRequestProperty("User-Agent","NetFox"); dFnu&u"
_C$SaQty[Q
79'N/:.
int responseCode=httpConnection.getResponseCode(); {E1^Wn1M
if(responseCode>=400) dJ{'b'#
{ _ukBp*u
processErrorCode(responseCode); ~c>]kL(,
return -2; //-2 represent access is error C7 9~@%T
} ITU6Eq
anUH'mcK*
{=y~O
String sHeader; :C#(yp
N#X(gEV
>>h0(G|
for(int i=1;;i++) XO/JnJ^B
{ P"+K'B7K3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QUc&f+~
//Utility.log(in.readLine()); l9NET
sHeader=httpConnection.getHeaderFieldKey(i); ^JB5-EtL(
if(sHeader!=null) @c%h fI
{ TaTw,K|/
if(sHeader.equals("Content-Length")) O-<nLB!Wf
{ =l}XKl->
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DDU)G51>d
break; FWpb5jc)3
} 6 &MATMR
} W -5wjc
else X]Ma:1+
break; ItQ3|-^
} ? y^t
} G5zsId dS
catch(IOException e){e.printStackTrace ();} p+{*&Hm5
catch(Exception e){e.printStackTrace ();} hKQg:30<
m<:g\_<
J|WkPv2
Utility.log(nFileLength); Uv=hxV[7y
|-vn,zpe
(d=knoo7A
return nFileLength; 1Qo2Z;h@
} R94ID@LF
uhr&P4EW
t|k-Bh:x
//保存下载信息（文件指针位置） rqi|8gKY
private void write_nPos() 0BHSeO,
{ ]}N&I_mU
try{ uJt*> ;Kp
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZfWF2%]<
output.writeInt(nStartPos.length); X}j_k=,C
for(int i=0;i<nStartPos.length;i++) dWDf(SS
{ }!5+G:JAh
// output.writeLong(nPos); ]1i1_AR'`
output.writeLong(fileSplitterFetch.nStartPos); ':?MFkYC
output.writeLong(fileSplitterFetch.nEndPos); =:7OS>x
} &^b mZj!
output.close(); $N17GqoC
} c UHKE\F
catch(IOException e){e.printStackTrace ();} Bez 7
catch(Exception e){e.printStackTrace ();} ~HyqHxy
} J~1=?</
2z=aP!9]
0HS"Oxx'
//读取保存的下载信息（文件指针位置） >=3ay^(Y2D
private void read_nPos() Z3nmC-NE
{ x[eho,6)
try{ )|i]"8I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D7(kkr:r
int nCount = input.readInt(); P{h$> 6c
nStartPos = new long[nCount]; W .bJ.hO*
nEndPos = new long[nCount]; 5R"(4a P
for(int i=0;i<nStartPos.length;i++) '?v-o)X
{ HPeN0=7>
nStartPos = input.readLong(); SRpPLY{:F
nEndPos = input.readLong(); -JB~yO?0
} Z3Y(g
input.close(); V|zatMHs
} I?IAZa)
catch(IOException e){e.printStackTrace ();} uMM?s?q
catch(Exception e){e.printStackTrace ();} :=^_N}
} VT`C<'
9~C$C
{qjw S1v
private void processErrorCode(int nErrorCode) 94xRKQ}
{ b'5L|1d
System.err.println("Error Code : " + nErrorCode); *[O)VkL\%i
} /?g:`NT
w%Tjn^d
>z1q\cz
//停止文件下载 k_%"#
public void siteStop() d(8X?k.S
{ Y1h)0_0
bStop = true; )M(-EDL>Qk
for(int i=0;i<nStartPos.length;i++) lDm0O)Dh!
fileSplitterFetch.splitterStop(); Z4'8x h)-
O&De!Gx
A +J&(7N
} j_2yTz"G-
} zd+<1R;
//负责部分文件的抓取 | ?])]F
**FileSplitterFetch.java %N }0,a0
*/ j6{9XIRo_
package NetFox; bB`p-1
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@u}1 S1
import java.io.*; Xeo2 < @[
import java.net.*; 'WLh D<
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public class FileSplitterFetch extends Thread { XrD@q
z7'C;I
1'{A,!
String sURL; //File URL BVk&TGa;[$
long nStartPos; //File Snippet Start Position 8LM 91
long nEndPos; //File Snippet End Position /MUa b*h
int nThreadID; //Thread's ID vuE 1(CR
boolean bDownOver = false; //Downing is over eL7\})!W
boolean bStop = false; //Stop identical +Tug.[A
FileAccessI fileAccessI = null; //File Access interface pN ^^U[
0X"D!G):
#.kDin~!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]NrA2i?
{ u=u#6%
this.sURL = sURL; 0pu=,
this.nStartPos = nStart; cK(S{|F
this.nEndPos = nEnd; CHPu$eu
nThreadID = id; }b5If7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OLS.0UEc
} -l#h^
a J&)-ge
vUU)zZB~
public void run() @L ,hA v^
{ 4)XZ'~|
while(nStartPos < nEndPos && !bStop) 2!+saf^-,
{ sF`ELrR \
qz .{[l
+7]]=e<[E
try{ ?onTW2cG;
URL url = new URL(sURL); FnFJw;:,{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z*Fxr;)d
httpConnection.setRequestProperty("User-Agent","NetFox"); zJ2dPp~u
String sProperty = "bytes="+nStartPos+"-"; sAG#M\A6
httpConnection.setRequestProperty("RANGE",sProperty); 9nrH 6]
Utility.log(sProperty); 4.}{B_)LK
AQH\ ;L
97%S{_2m/
InputStream input = httpConnection.getInputStream(); a*4l!-7
//logResponseHead(httpConnection); ogrh"
!b0ANIp
U)n+j}vi
byte[] b = new byte[1024]; quPNwNy
int nRead; L93&.d@m9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;n)9
{ gh{Z=_
nStartPos += fileAccessI.write(b,0,nRead); */ ~_3
//if(nThreadID == 1) vCB0x:/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y%B:IeF}
} W".: 1ov#B
[Pnk@jIk4
_4]GP3`
Utility.log("Thread " + nThreadID + " is over!"); l,pI~A`w_
bDownOver = true; X_6h8n}i
//nPos = fileAccessI.write (b,0,nRead); yp}a&Dg
} BmP!/i_
catch(Exception e){e.printStackTrace ();} +l "z
} t69C48}15
} G{ 9p.Q
,'E+f%
#H;yXsR`
//打印回应的头信息 y]5c!N %8
public void logResponseHead(HttpURLConnection con) j6NK7Li
{ 9 ^G.]W]
for(int i=1;;i++) iIe\mV
{ 1+f>tv
String header=con.getHeaderFieldKey(i); <]jKpJ{3N
if(header!=null) j~IX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /R2K3E#
Utility.log(header+" : "+con.getHeaderField(header)); W.fsW<{4j
else rX-V0
break; 0pYCh$TL1
} 7NY9UQ
} _|!FhZ
jgfl|;I?pg
w*E0f?s
public void splitterStop() Q>,EYb>wI
{ L1'#wH
bStop = true; ^+hqGu]M
} U=<d;2N#
@.PVUP
lBbUA)z6
} Z;nbnRz
'DB4po.
Xlw8>.\
/* 6WN1DW
**FileAccess.java /n9yv
*//文件访问(定位，写) zj?^,\{A
package NetFox; Y_H|Fl^
import java.io.*; sC/5N
?W#>9WQi
errT7&@,A
public class FileAccessI implements Serializable{ E7_)P>aS5
: " ([i"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Vz"Ja
RandomAccessFile oSavedFile; K,VN?t<h
long nPos; &_LFV@/
Kn WjP21
!yo/ F&6
public FileAccessI() throws IOException L7_qs+
{ 9q##)
this("",0); !zd]6YL$
} {iyO96YI[^
M=mzl750M
&m>yY{be
public FileAccessI(String sName,long nPos) throws IOException TTJFF\$?
{ m_ |:tU(t
oSavedFile = new RandomAccessFile(sName,"rw"); (#dwIBBFt
this.nPos = nPos; F|eKt/>e
oSavedFile.seek(nPos); A@-A_=a,
} /GzA89N(
63J_u-o
XzX-Q'i=n0
public synchronized int write(byte[] b,int nStart,int nLen) O[N}@%HMW
{ *bl*R';
int n = -1; $*%ipD}f
try{ @Gh?|d7bD
oSavedFile.write(b,nStart,nLen); "|2|Vju%
n = nLen; wTpjM@F?J|
} * 5H
catch(IOException e) 7+,6m!4
{ (-RZ|VdYg
e.printStackTrace (); y5td o'Ex
} sd@JQ%O
@E(_H$|E
5$v,%~$Xds
return n; @AXRKYQ{t
} Hcp)Q76X
F~NmLm
A,tmy',d"
} d!V;\w
{Hv/|.),hu
M@G <I]\
/* PRs[!EB6
**SiteInfoBean.java X&B2&e;
*/ $_j\b4]%
package NetFox; qdlz#-B
.,)C^hs@
Dlc=[kf9
public class SiteInfoBean { z!z+E%H^
(&25 8i,
{^r8uKo:~
private String sSiteURL; //Site's URL 'nK(cKDIG
private String sFilePath; //Saved File's Path WBo|0(#
private String sFileName; //Saved File's Name .>5KwEK~
private int nSplitter; //Count of Splited Downloading File 7*!h:rg
xq?9w$
_I("k:E7
public SiteInfoBean() 52*9q!
{//nSplitter的缺省值为5 @~4Q\^;NX
//default value of nSplitter is 5 e?Pzhha
this("","","",5); 5 A/[x$q
} ,rvw E
sH//*y
E>/kNl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $VWeo#b
{ B.wRZDEvc
sSiteURL= sURL; _QD##`<
sFilePath = sPath; `N+A8
sFileName = sName; bNUb
this.nSplitter = nSpiltter; mkA1Sh{hX>
RXMzwk
u7rA8u|TO
} eXHk6[%[
+=XDNSw
(J c} K
public String getSSiteURL() ZT UaF4k j
{ MwoU>+XB
return sSiteURL; QB<9Be@e
} ]Iku(<*Ya
9#:b+Amzz
!xU1[,9
public void setSSiteURL(String value) ]et4B+=i
{ q*^Y8s~3I
sSiteURL = value; uXs.7+f
} 4LO U[D
5t`:=@u
Pj4WWKX
public String getSFilePath() -&PiD
{ *z2G(Uac
return sFilePath; bCM&Fe0GM
} 8hx4s(1!
0!WF,)/T7i
h$#QRH
public void setSFilePath(String value) K`=O!;
{ VDCG 5QP6(
sFilePath = value; '=|2, H]
} =B}a +0u!
#WBlEVx;Z
&kR+7
public String getSFileName() +*dG'U6
{ MXSN <
return sFileName; }gk37_}X\I
} l8I`%bu
gW{<:6}!*
'cs!(z-{x
public void setSFileName(String value) KO`ftz3 +
{ k7rFbrLZ
sFileName = value; % D]vKv~<
} _l?InNv
(!-gX"<b
-E6#G[JJ
public int getNSplitter() (1~d/u?2\
{ 7 Jxhn!
return nSplitter; sV8}Gv a
} XcOfQs
AXUSU(hU
_:hrm%^
public void setNSplitter(int nCount) o:H^ L,<Tl
{ oCE=!75
nSplitter = nCount; ~F?vf@k
} /az}<r8
} RlRkw+%m
8dg\_H_
!.(Kpcrg
/* uSZCJ#'G
**Utility.java axJuJ`+Y
*/ =oZHN,
package NetFox; mWOW39Ku
>]6f!;Rt
M2K{{pGJ[&
public class Utility { `6`p~
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dGxk ql
public Utility() )tH.P: 1~,
{ J~=bW\^I
+_.k\CRms
:}QBrd
} T&M*sydA
?C(' z7
//线程睡眠 ) >_xHc?
public static void sleep(int nSecond) Vu @2
{ ?xftr(
try{ EV1x"}D A_
Thread.sleep(nSecond); 81m3j`b
} /RVy?)hVT#
catch(Exception e) \rXmWzl{
{ gN2$;hb?
e.printStackTrace (); @J`o pR
} Bw;gl^:UG
} 9g*O;0uz
=?o,' n0
//日志 $]V,H"
public static void log(String sMsg) PUt\^ke
{ C$"N)6%q
System.err.println(sMsg); Y(aEp_kV
} D{-h2=V
"4Joou"U
;yfKYN[
public static void log(int sMsg) ;kSRv=S
{ 3Go/5X/
System.err.println(sMsg); -s?f<f{
} glMYEGz6p
} jZjWz1+
o!R.QI^2VT
,g69?w
/* r[doN{%
**TestMethod.java 75@!j[QL<
*/ cB$OkaG#
package NetFox; oXC|q-(C
1D*oXE9Ig
gN,O)@N'd3
public class TestMethod { [/h3HyZ.
{e'P*j
0P{^aSxTP
public TestMethod() 1M1|Wp
{ ///xx/weblogic60b2_win.exe `IP?w&k)
try{ iA~LH6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #Hn<4g"AjM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o#"U8N%r
SiteFileFetch fileFetch = new SiteFileFetch(bean); KCBA`N8
fileFetch.start(); L/ L#[
} z7vc|Z|
catch(Exception e){e.printStackTrace ();} 5j8aMnvs
/ .wO<l=
gmdJ8$
} pUcN-WA
BiFU3FlTf
(/mR p
public static void main(String[] args) m:6^yfS
{ 1X8P v*,
new TestMethod(); y4\(ynk
} JfOBZQ
} a&^HvXO(>(
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