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)); PQ6T|>
} r$94J'_
for(int i=0;i<nEndPos.length-1;i++) "sdcP8])d
{ <.;@ksCPW{
nEndPos = nStartPos[i+1]; vM5k4%D
} :O5Tr03z
nEndPos[nEndPos.length-1] = nFileLength; G[ ,,L
} \a\^(`3a[
} aeLBaS
o]dK^[/*
\o0z@Ntq
//启动子线程 6-D%)Z(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PY[Sz=[
for(int i=0;i<nStartPos.length;i++) /,=Wy"0TJ
{ e!TG< (S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =ltbSf7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TXA. 6e
nStartPos,nEndPos,i); H't`Q&]a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~3LhcU-
fileSplitterFetch.start(); f<Va<TL6-
} FEge+`{,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J,CJPUf&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /+Wb6{lY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Dh*~U:6$g
nEndPos = " + nFileLength); n P0Ziu'{
// fileSplitterFetch[nPos.length-1].start(); C~3@M<X
B)_!F`9
F! |TW6)gv
//等待子线程结束 I|Vk.,
//int count = 0; jB}_Slh1j
//是否结束while循环 :_W0Af09
boolean breakWhile = false; Tb>IHoil
8:;u v7p
k#{lt-a/
while(!bStop) 3(oZZz
{ I8E\'`:<
write_nPos(); V#n?&-{V
Utility.sleep(500); 1^n5CI|7u
breakWhile = true; 8A`p
qg) Af
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for(int i=0;i<nStartPos.length;i++) \c5#\1<
{ 'p4da2%
if(!fileSplitterFetch.bDownOver) p{\qSPK
{ ]w1BJZa36
breakWhile = false; (ouRf;\6$8
break; wz*)L (pP
} U'f$YVc
} wa-_O<
if(breakWhile) 'fp<FeTg
break; NgDZ4&L
T%N~oa
\@iOnRuHn9
//count++; "<g?x`iz
//if(count>4) -f-O2G=
// siteStop(); t-?KKU8
} Z<$E.##
8`R +y
D}k-2RM2k
System.err.println("文件下载结束！"); N,'[:{GOY
} r7]?g~zb
catch(Exception e){e.printStackTrace ();} iA1;k*)q
} W(]E04
y \mutm
a:(: :m
//获得文件长度 %_%f#S
public long getFileSize() KoxGxHz^Y3
{ {="Su{i}}
int nFileLength = -1; lEVQA*u[
try{ 2l\D~ y
URL url = new URL(siteInfoBean.getSSiteURL()); oF 1W}DtA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); khKv5K#)
httpConnection.setRequestProperty("User-Agent","NetFox"); cq@_*:~Or
gKm@B{rC
U_N5~#9
int responseCode=httpConnection.getResponseCode(); 5<:VJC<
if(responseCode>=400) m=("N
{ Sm*Jysy`
processErrorCode(responseCode); HL}sqcp
return -2; //-2 represent access is error o[Wagg.%
} % RBI\tj
O=!)})YG
)Yy#`t
String sHeader; ,_5YaX:<4
ZmYSi$B
{m*V/tX
for(int i=1;;i++) :!Y?j{sGU
{ _taHf %\4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `K@df<}%*,
//Utility.log(in.readLine()); d-#u/{jG)
sHeader=httpConnection.getHeaderFieldKey(i); #*7/05)
if(sHeader!=null) FJwZo}<6E
{ 6S&=OK^
if(sHeader.equals("Content-Length")) 9wDBC~.
{ @FnI?Rx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ok~W@sYST
break; >TQBRA;'
} GP7)m
} w50Bq&/jX
else fW4cHB9|
break; I]WeZ,E
} ?( dYW7S
} Vm,f3~
catch(IOException e){e.printStackTrace ();} r%m7YwXo
catch(Exception e){e.printStackTrace ();} kS\.
U_ ?elz\
,SE$Rh
Utility.log(nFileLength); DS,FVh".|
#ejw@bd
Jv4D^>yj[
return nFileLength; +DbWMm
} "o5gQTwb
mC[U)` ey
9Qs"X7iH
//保存下载信息（文件指针位置） tci%=3,)
private void write_nPos() HC;I0&v>
{ 8t*%q+Z
try{ 5w [=
output = new DataOutputStream(new FileOutputStream(tmpFile)); mB|mt+
output.writeInt(nStartPos.length); M_e$l`"G
for(int i=0;i<nStartPos.length;i++) *|gs-<[#X
{ eV{FcJha
// output.writeLong(nPos); zcD_}t_K
output.writeLong(fileSplitterFetch.nStartPos); "<jEI /
output.writeLong(fileSplitterFetch.nEndPos); mZ0oa-Iy
} %Dr4~7=7a
output.close(); 0@FM^ejA#
} e ka@?`
catch(IOException e){e.printStackTrace ();} @BHS5^|
catch(Exception e){e.printStackTrace ();} Sfoy8<j
} "aCb;2Rs
CAo )v,f
1f pS"_}
//读取保存的下载信息（文件指针位置） 4gkV]" H!
private void read_nPos() #Wc #fP
{ T m@1q!G
try{ 3}#XA+Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b#I*~
int nCount = input.readInt(); >2Qqa;nx|
nStartPos = new long[nCount]; ?lwQne8/
nEndPos = new long[nCount]; kj3o1Y
for(int i=0;i<nStartPos.length;i++) u0oYb_Yv
{ M6hvi(!X2
nStartPos = input.readLong(); vb"dX0)<
nEndPos = input.readLong(); 1-NX>E5
} dj'8x48H2W
input.close(); nwZr3r
} ,<P[CUD&&
catch(IOException e){e.printStackTrace ();} *A1TDc$
catch(Exception e){e.printStackTrace ();} }jY[| >z
} #!d^3iB2
R$;&O. 5M
[ls ?IFg
private void processErrorCode(int nErrorCode) xm10
{ /E4}d=5L
System.err.println("Error Code : " + nErrorCode); ,8"[ /@
} C}P \kDM
R,5$ 0_]|+
(~pEro]?+)
//停止文件下载 ~~:8Yv[(
public void siteStop() 97))'gC
{ >5@vY?QXO
bStop = true; })0 7u
for(int i=0;i<nStartPos.length;i++) %M,d/4=P
fileSplitterFetch.splitterStop(); `jQ}^wEgu
&<P^Tvqq&
4bFVyv
} R5;eR(24G
} `i)ePiE
//负责部分文件的抓取 ?5YmE(v7
**FileSplitterFetch.java PD T\Q\J^X
*/ +-!|%jG`%v
package NetFox; h. (;GJO
cD`O+WA2K
$t H.np
import java.io.*; B?ob{K@
import java.net.*; PUZXmnB
F%+rOT<5
hYUV9k:
public class FileSplitterFetch extends Thread { ~B*\k^t`
vwH7/+
.q9|XDqQc
String sURL; //File URL oJJk
long nStartPos; //File Snippet Start Position 2SPFjpG8n
long nEndPos; //File Snippet End Position .f<VmUca
int nThreadID; //Thread's ID fYQi#0drn
boolean bDownOver = false; //Downing is over i`nw"8
boolean bStop = false; //Stop identical '/Cz{<,
FileAccessI fileAccessI = null; //File Access interface Ce'2lo
Y$$?8xr ~
2l(j 4~g
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j% USu+&
{ 8(/f!~
this.sURL = sURL; p,u<gJUL
this.nStartPos = nStart; KIBZQ.uG
this.nEndPos = nEnd; |Sv#f2`
nThreadID = id; 2d;xAX]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 PW//8lsR
} >Wit"p
Qp{-!*
6ym)F!t8l
public void run() |wb(rua
{ hG;=ci3EE
while(nStartPos < nEndPos && !bStop) y'O{8Q8T
{ .QQI~p0:
t{s*3k/
g7z9i[
try{ JR<-'
URL url = new URL(sURL); .d!*<`S|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3R:i*8C
httpConnection.setRequestProperty("User-Agent","NetFox"); <.(/#=2
String sProperty = "bytes="+nStartPos+"-"; z slEUTj)
httpConnection.setRequestProperty("RANGE",sProperty); 1HWJxV"
Utility.log(sProperty); j4SGA#;v
Bt7v[Ot
A^@<+?
InputStream input = httpConnection.getInputStream(); L.:QI<n
//logResponseHead(httpConnection); _%TeTNY#
^r :A^q
)9jQ_
byte[] b = new byte[1024]; N&h!14]{Z
int nRead; 6Oba}`)q9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1`_)%Y[ZJ
{ dsZ( D:)
nStartPos += fileAccessI.write(b,0,nRead); 4bzn^
//if(nThreadID == 1) w]-iM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OLup`~
} G(\1{"!
}~'Wz*Gm
v!h-h&p O7
Utility.log("Thread " + nThreadID + " is over!"); y/6LMAI
bDownOver = true; |B$\3,
//nPos = fileAccessI.write (b,0,nRead); A y[L{!)2{
} KmOa^vY1.T
catch(Exception e){e.printStackTrace ();} xLK0~|_#!
} 'R'a/ZR`B7
} 9:w,@Phe
-86:PL(I"
FF!g9>
//打印回应的头信息 qML*Kwg
public void logResponseHead(HttpURLConnection con) .%Q Ea_\
{ Byj~\QMD|
for(int i=1;;i++) -?1J+}?
{ iPO S
String header=con.getHeaderFieldKey(i); HYmUxheN2
if(header!=null) Hll}8d6[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ht^2)~e~:
Utility.log(header+" : "+con.getHeaderField(header)); Py]ci`27
else c!^}!32j)
break; \o)4m[oF
} <1.mm_pw
} -%) !XB
;O|63
2B dr#qr
public void splitterStop() xF|*N<9(</
{ .LR>&N_U
bStop = true; Z?'|9FM
} ea>\.D-S
B&N&eRAE
T@Z{KV"S
} #de^~
-Ep6.v
aW$nNUVD
/* }3y\cv0ct
**FileAccess.java 4yv31QG$
*//文件访问(定位，写) RcP5].^T
package NetFox; iZ\z!tHR
import java.io.*; ^(vd8&71
|raQ]b@t&
beZ| i 1:
public class FileAccessI implements Serializable{ n`Iy7X
3*2pacHpE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E}&jtMRUt
RandomAccessFile oSavedFile; MXV4bgltT
long nPos; 3~xOO*`o
=W*`HV-w
@0'|Uygn
public FileAccessI() throws IOException *7ro [
{ bR,Iq}p
this("",0); JhIK$Ti
} p;=(-4\V}
(k&aD2PH
%]oLEmn}y
public FileAccessI(String sName,long nPos) throws IOException gj X1b2
{ {U-EBXV
oSavedFile = new RandomAccessFile(sName,"rw"); IuW10}"9
this.nPos = nPos; Yg?{x@
oSavedFile.seek(nPos); Ps\^OJR
} t&]Mt7
f"^tOgGH
6J+ZeBk??
public synchronized int write(byte[] b,int nStart,int nLen) 9(j!#`O7&
{ 6E]rxps}"
int n = -1; zAUfd[g
try{ TeqsP1{?
oSavedFile.write(b,nStart,nLen); Q*(o;\s
n = nLen; Mwc3@
} {2@96o2}
catch(IOException e) jMbK7 1K%
{ g>zL{[e!
e.printStackTrace (); LWV`xCr8R
} -;"l5oX
J[wXG6M
]]3D` F}
return n; -1JHhRr]
} u`|fmVI
\]%U?`A
B4aZ3.&W
} 3/FB>w gt
oD\+ 5[x
@CF4:NNHw
/* >O~5s.1u
**SiteInfoBean.java nVzo=+Yp
*/ V}qmH2h
package NetFox; Dm#k-y
a"0~_=
55p=veq \
public class SiteInfoBean { 90}B*3x
F9W5x=EK\
I r~X#$Upc
private String sSiteURL; //Site's URL n]Y _C^
private String sFilePath; //Saved File's Path }DaYO\:yK*
private String sFileName; //Saved File's Name kM`#U *j
private int nSplitter; //Count of Splited Downloading File W$S.?[X
|3m%d2V*hF
uLF55:`<
public SiteInfoBean() oVW?d]R
{//nSplitter的缺省值为5 mM.&c5U
//default value of nSplitter is 5 p;Kr664
this("","","",5); qE{S'XyM,
} ]XU#i#;c
(xL=X%6a
i;Y^}2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n TG|Isa
{ =C|^C
sSiteURL= sURL; J~.kb k
sFilePath = sPath; B!@0(A
sFileName = sName; pdSyx>rJ
this.nSplitter = nSpiltter; *gVv74;;
ez{&Y>n
6bba}P
} LKcrr;
@HI5;z
Je,8{J|e
public String getSSiteURL() ;rgsPVbVf
{ *en{pR'
return sSiteURL; fF%r$`2
} jQ*Qh
o@. !Z8
s8Oz^5p(
public void setSSiteURL(String value) e-mlvi^-
{ fp0Va!T(V
sSiteURL = value; 1~Nz6
} ~\P.gSiz
1 <+^$QL
uk,f}Xc
public String getSFilePath() =xoTH3/,>
{ 7|rT*-Ia
return sFilePath; 1o%Hn"uG
} t2iFd?
rtm28|0H'
4hIC&W~f
public void setSFilePath(String value) \m&:J>^
{ r DuG["
sFilePath = value; Lrq&k40y
} V EzIWNV
o;fQ,rP%
^-ZqS
public String getSFileName() 0W> ",2|z
{ ;q Z2V
return sFileName; K#jm6Xh?E
} )1/O_N6C
6F2}|c
rQJoaP+\q
public void setSFileName(String value) YC~+r8ME$j
{ F/8y p<_r
sFileName = value; 6]VTn-
} M:x(_Lu
v;SJgZK
8J} J;Ga
public int getNSplitter() M4| L
{ Sc&_6}K
return nSplitter; S:gP\Atf>
} r_G`#Z_5F
!SnpesTn
8Ex0[e
public void setNSplitter(int nCount) bTj,5,8i
{ <$E8T>U
nSplitter = nCount; Z_%>yqDC
} /-T%yuU
} lI9 3{!+>
5s;#C/ZZ
c!zu0\[Id
/* W8)GT`\
**Utility.java f&:g{K
*/ qpZ".
package NetFox; eX\t]{\oC
j.o)!SA
9E5B.qlw$l
public class Utility { FE`J.aw^X
XZhhr1-<a
^#+9v
public Utility() /=%4gWtr
{ >|<6s],v
J{H475GqiT
}U9e#>ex
} d<]/,BY'
)j](_kvK
//线程睡眠 V%))%?3x_
public static void sleep(int nSecond) Ex<loVIrP$
{ I8m(p+Z=
try{ /Mv'fich(
Thread.sleep(nSecond); m{~r6@
} YV+e];s
catch(Exception e) B6BOy~B0
{ @I%m}>4Jm
e.printStackTrace (); b+kb7
} X:YxsZQ5Y
} Z=#!FZ{
"QMHY\C
//日志 ^VA)vLj@
public static void log(String sMsg) _QQO&0Z
{ =&vV$UtV
System.err.println(sMsg); YPN|qn(
} `|gCbs95
GFvOrRlP\
s;bqUY?LD
public static void log(int sMsg) BzDS
{ T6tJwSS4:
System.err.println(sMsg); bcQ$S;U)
} K~uoZ~_gA
} *Nv<,Br,F
Xh?{%?2
T+I|2HYqOj
/* N7|ctO
**TestMethod.java 6uDNqq
*/ NS\'o )J
package NetFox; kM.zX|_
/Z^+K
Q~jUZ-qN
public class TestMethod { @rE>D
a}6Wo=
E]bjI$j
public TestMethod() >scEdeM
{ ///xx/weblogic60b2_win.exe tYnNOK*|
try{ xSw ^v6!2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ax&+UxQ0|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~#wq sm
SiteFileFetch fileFetch = new SiteFileFetch(bean); $N~8^6
fileFetch.start(); )F:hv[iv
} TtHqdKL
catch(Exception e){e.printStackTrace ();} o_?YYw-:
-q[?,h
7uYJ_R
} bEM-^SR
h9No'!'!
O`*}N1No[
public static void main(String[] args) *edB3!!
{ ondF
new TestMethod(); nP] ~8ViS
} 'En6h"{
} t'^/}=c-
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