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)); ?)-6~p 4N
} Mc.{I"c@
for(int i=0;i<nEndPos.length-1;i++) |gI>Sp%Fu
{ pFS@yHs
nEndPos = nStartPos[i+1]; Uo >aQk
} (0.oE%B",1
nEndPos[nEndPos.length-1] = nFileLength; [tkx84M8
} f;^ +q-Q
} _ +DL
FzX ;~CA
>[aR8J/U
//启动子线程 ^g*Sy, A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ={%'tv`
for(int i=0;i<nStartPos.length;i++) )iw-l~y;
{ B`e/ /
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ck )W=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Zq85q
nStartPos,nEndPos,i); L" ejA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^(^P#EEG
fileSplitterFetch.start(); m@XX2l9:9
} ISC>]`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `[5xncZ-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y"bm4&'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,5 ka{Q`K
nEndPos = " + nFileLength); ((A@VcX
// fileSplitterFetch[nPos.length-1].start(); 0a89<yX
"O>~osj
g)czJ=T2
//等待子线程结束 \JM6zR^Ef
//int count = 0; m8F$h-
//是否结束while循环 Ag9GYm
boolean breakWhile = false; 1ARtFR2C{b
}{N#JTmjB#
'O)v@p "
while(!bStop) <@(\z
{ >u> E !5O
write_nPos(); b\ED<'
Utility.sleep(500); :bct+J}l~
breakWhile = true; O80Z7
T+Re1sPr?
> Hv9Xz
for(int i=0;i<nStartPos.length;i++) `3\U9ZH23
{ I%r7L
if(!fileSplitterFetch.bDownOver) }PK4 KRn
{ TNqL ')f
breakWhile = false; 4j3_OUwWZx
break; ivgX o'=
} 4A@HR
} ]2m=lt1
if(breakWhile) -Ct+W;2
break; 2?%*UxcO
<lFHmi$qt{
sC\?{B0r
//count++; R?)Yh.vi=t
//if(count>4) it H
// siteStop(); _DSDY$Ec
} #9TL5-1y
aU;X&g+_)
+!u9_?Tp
System.err.println("文件下载结束！"); ^Ak?2,xB#+
} h!dij^bD
catch(Exception e){e.printStackTrace ();} W^3 Jg2gE
} q0%QMut%
!QVhP+l'H
-%J9!(
//获得文件长度 %TI3Eb
public long getFileSize() }OIe!
{ tF,`v{-up
int nFileLength = -1; 3L==p`
try{ @:w^j0+h
URL url = new URL(siteInfoBean.getSSiteURL()); D,..gsg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W[I[Xg&
httpConnection.setRequestProperty("User-Agent","NetFox"); ugN%8N
\1<aBgKi
w|G7h=
int responseCode=httpConnection.getResponseCode(); &I ~'2mpk
if(responseCode>=400) `%[m%Y9h
{ 4j0;okQWV'
processErrorCode(responseCode); }8 ;,2E*z
return -2; //-2 represent access is error lmcgOTT):
} nnhI]#,a{
U^[AW$WzU
K+/wJ9^B
String sHeader; V(K;Gc
MjQ>&fUK
XC<'m{^(m
for(int i=1;;i++) 9E5*%Hu_
{ y)|d`qC\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IIMf\JdM
//Utility.log(in.readLine()); B7qi|Fw
sHeader=httpConnection.getHeaderFieldKey(i); N4qBCBr(
if(sHeader!=null) rg[#(
{ ,]JIp~=nsh
if(sHeader.equals("Content-Length")) ]Rf$&7`g{
{ (ZF~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (5`(H.(
break; TPx0LDk%(
} jp_)NC/~g
} 07qjWo/t
else 0;1O;JRw
break; ZX-A}
} f[NxqNn
} 4j+M<g
catch(IOException e){e.printStackTrace ();} bly `mp8#
catch(Exception e){e.printStackTrace ();} !}mM"|<
KX\=wFbP)
evE:FiDm(j
Utility.log(nFileLength); EN^L.q9#
XpKeN2=p
`v(!IBP|
return nFileLength; `|nJAW3
} DcRoW
xG4 C 6s
FS)C<T]t
//保存下载信息（文件指针位置） V@G|2ZI
private void write_nPos() /i!/)]*-
{ l:~ >P[
try{ OWr\$lm@z$
output = new DataOutputStream(new FileOutputStream(tmpFile)); /55 3v;l<
output.writeInt(nStartPos.length); _Nz?fJ:$@
for(int i=0;i<nStartPos.length;i++) g("[wqgG
{ n[a%*i6x
// output.writeLong(nPos); k^q~2
output.writeLong(fileSplitterFetch.nStartPos); yJ; ;&
output.writeLong(fileSplitterFetch.nEndPos); LDo~
} 4e[ 0.2?
output.close(); gi_f8RP=2a
} B.Z5+MgM
catch(IOException e){e.printStackTrace ();} Ql}#mC.>/
catch(Exception e){e.printStackTrace ();} PEtr8J$uB
} SrdCLT8
L?(1 [jB4G
|M?VmG/6
//读取保存的下载信息（文件指针位置） \Z/0i|
private void read_nPos() ll"6KI'X
{ caTKi8
try{ Hs.5@l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,I f9w$(z
int nCount = input.readInt(); sPX~>8}|VP
nStartPos = new long[nCount]; TDR#'i
nEndPos = new long[nCount]; XPi5E"
for(int i=0;i<nStartPos.length;i++) ,{RWs^W2
{ FePWr7Ze
nStartPos = input.readLong(); G>2: WQ/
nEndPos = input.readLong(); y8di-d3_
} ,f~8:LHq
input.close(); cbx( L8
} ?+{qmqN
catch(IOException e){e.printStackTrace ();} eGrxS;NY
catch(Exception e){e.printStackTrace ();} @7Nc*-SM
} 4Z{ r
LtDGu})1
LgSVEQb6\|
private void processErrorCode(int nErrorCode) 5[+E?4,&
{ =:^f6"p&Z
System.err.println("Error Code : " + nErrorCode); WWIQ6EJO
} l\=He
W^9=z~-h
+d8?=LX
//停止文件下载 5[$Tpn#K7
public void siteStop() yuB\Z/
{ +&)&Ny$W
bStop = true; ==W] 1@s
for(int i=0;i<nStartPos.length;i++) u6p nO
fileSplitterFetch.splitterStop(); 4,6nk.$yN
}zwHUf9q1
b0Fr]oGp
} dO[pm0
} x4S0C[k
//负责部分文件的抓取 /{\mV(F(
**FileSplitterFetch.java sJcwN.s
*/ k/#321Z
package NetFox; %-, -:e
mwqe@7
h*zHmkFR
import java.io.*; 3ES3,uR
import java.net.*; RVe UQ%
tv7A&Z)Rh
08 aZU
public class FileSplitterFetch extends Thread { b+ v!3|
UkXf)
g:>Mooxzi
String sURL; //File URL %'i`Chc^!;
long nStartPos; //File Snippet Start Position ;K<W<v5m0N
long nEndPos; //File Snippet End Position J |TA12s
int nThreadID; //Thread's ID TYh_uox6
boolean bDownOver = false; //Downing is over hiA%Tq?
boolean bStop = false; //Stop identical }CXL\,;
FileAccessI fileAccessI = null; //File Access interface FYu=e?L
s+yX82Y
bMpCQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #}{1>g{sXt
{ 7IH^5r
this.sURL = sURL; 5PU$D`7it
this.nStartPos = nStart; x_TtS|
this.nEndPos = nEnd; {:r8X
nThreadID = id; H+ Y+8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }28,fb /
} F(Iq8DV
Ohmi(s
nXuoRZ
public void run() 27!9LU
{ #=B~} _
while(nStartPos < nEndPos && !bStop) w$5#jJX\
{ 3d|n\!1r
:. ja~Q
<MH| <hP
try{ ?YO$NYwE
URL url = new URL(sURL); zg=F;^oZ<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4uG:*0{Yx
httpConnection.setRequestProperty("User-Agent","NetFox"); Nn;p1n dN
String sProperty = "bytes="+nStartPos+"-"; WhHnF*I
httpConnection.setRequestProperty("RANGE",sProperty); z rV
Utility.log(sProperty); zT5@wm
/"M7YPX;
-K K)}I`
InputStream input = httpConnection.getInputStream(); `II/nv0jn
//logResponseHead(httpConnection); L:g!f
$|yO mh
ywRwi~
byte[] b = new byte[1024]; \D37l_
int nRead; ]7`)|PJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;w_f^R #
{ eQUm!9)
nStartPos += fileAccessI.write(b,0,nRead); aI6fPQe
//if(nThreadID == 1) . !|3a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,\BGxGNAmV
} XfXqq[\N
pU|SUM
StP7t
Utility.log("Thread " + nThreadID + " is over!"); Q'~2,%3<
bDownOver = true; [z1[4
//nPos = fileAccessI.write (b,0,nRead); T53|*~u
} .D`""up|{
catch(Exception e){e.printStackTrace ();} G3&l|@5
} P'4jz&4
} mqg[2VTRP
+h$)l/>:
c?NXX&
//打印回应的头信息 zl W5$cC[
public void logResponseHead(HttpURLConnection con) -nQ:RHnd
{ d|9B3I*I
for(int i=1;;i++) Lit@ m2{\
{ tDl1UX
String header=con.getHeaderFieldKey(i); K)AJx"
if(header!=null) Q`dzn=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %y/8i%@6
Utility.log(header+" : "+con.getHeaderField(header)); #*[G,s#t^
else :Q\{LBc
break; >~kSe=Hsb4
} _O-ZII~
} uV:;q>XM'%
xYJ|G=h&A
vElVw. P
public void splitterStop() zd+_ BPT
{ ;MqH)M
bStop = true; cj:!uhZp7
} Ed%8| M3
J0e~s
RfMrGC^?
} (P-Bmu!s
{:VUu?5-t;
szY=N7\S*
/* k{op,n#
**FileAccess.java Q]Fm4
*//文件访问(定位，写) 'Lw4jq
package NetFox; j7vp@l6`L
import java.io.*; Zjz< Q-
\k{UqU+s
t$sL6|Ww}o
public class FileAccessI implements Serializable{ |Go?A/'
&J)q_Z8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D2`tWRm0
RandomAccessFile oSavedFile; ic}M)S FD;
long nPos; HCh;Xi
@Fp-6J
!vU$^>zo~
public FileAccessI() throws IOException L--
{ %=:*yf>}
this("",0); /-ebx~FX&
} eGZX6Q7m
Y~qv 0O6K
KKR@u(+"a
public FileAccessI(String sName,long nPos) throws IOException YEZd8Y
{ >9o(84AxIH
oSavedFile = new RandomAccessFile(sName,"rw"); /qW5M4.w
this.nPos = nPos; 17Q1Xa
oSavedFile.seek(nPos); }U=|{@%
} q$$:<*Uy
e>-a\g
fX,L;Se"
public synchronized int write(byte[] b,int nStart,int nLen) 6B)3SC
{ !$"DD[~\
int n = -1; -S]yXZ
try{ A4,tv#z
oSavedFile.write(b,nStart,nLen); OC|9~B1
n = nLen; g0m6D:f
} Th&* d;
catch(IOException e) '/^bO#G:
{ pSQ)DqW
e.printStackTrace (); y9?~^pTx
} uaMf3HeYV
B5>1T[T'-
>^#OtFHuT)
return n; TO.71x|
} H+:SL $+<o
v$R+5_@[l
FhZ^/= As
} i<N[sO
_~aFzM
(R_#lRaQ
/* [C PgfVz
**SiteInfoBean.java H[ 6L!
*/ tn-_3C
package NetFox; m_Owe/BC#m
IL?mt2IQ>
\#P>k;D
public class SiteInfoBean { D(}w$hi8
Y<U"}}
`C~RA,M
private String sSiteURL; //Site's URL .z/M (
private String sFilePath; //Saved File's Path WPBn?vb0<
private String sFileName; //Saved File's Name HS{a^c%
private int nSplitter; //Count of Splited Downloading File )J?Nfi%
~n:dHK`
~$1Zw&X
public SiteInfoBean() -@49Zh2'
{//nSplitter的缺省值为5 D-8NDa(`
//default value of nSplitter is 5 B+G,v:)R6z
this("","","",5); {EKzPr/
} cd36f26`"w
vEJ2d&
9$&+0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cPh U qET
{ H6ff b)&
sSiteURL= sURL; U$[C>~r
sFilePath = sPath; v:*t5M >
sFileName = sName; u<x2"0f
this.nSplitter = nSpiltter; =VMV^[&>
<eU28M?\
c+PT"/3
} >#}MDwKZD
6fvzTd},
>hcA:\UPk
public String getSSiteURL() VeixwGZ.
{ )3_I-Ia
return sSiteURL; (?SK< 4!
} !r:X`~\a
t.sbfLu
3.q%?S}*
public void setSSiteURL(String value) uJz<:/rwZ-
{ O)ks
sSiteURL = value; 6"^Yn.
} wB6ILTu1
ViV"+b#gu
}."3&u't
public String getSFilePath() c@RMy$RTF
{ $x,?+N
return sFilePath; i>!7/o
} [6@{^
sY4sq5'!
i"=6n>\
public void setSFilePath(String value) 1O bxQ_x
{ Sa!r ,l
sFilePath = value; ]3@6o*R;
} pkjf5DWp
I@VhxJh
z=TaB^-)
public String getSFileName() }mRus<Ax
{ ]>R|4K_
return sFileName; `ReTfz;o
} QJc3@
+0U{CmH
lWS@<j
public void setSFileName(String value) f,9jK9/$
{ (~F{c0\C
sFileName = value; ;D^%)v/i
} ?Xm!;sS0
8H4"mxO
Jx;"@
public int getNSplitter() o:kiIZ]
{ ~F8M_
return nSplitter; `IQ01FuP
} :[:5^R
6e,|HV
D>9~JHB
public void setNSplitter(int nCount) tx}}Kd
{ J(*qOGBD
nSplitter = nCount; aY8"Sw|4
} >jEn>H?
} Xz)UH<
'Eds0"3
{@Y|"qIN
/* h8;B+#f`
**Utility.java 6~8A$:
*/ 1{N73]-M:
package NetFox; `YTagUq7
70NQ9*AAy
~[|&)}q
public class Utility { )(~s-x^\z@
c"BFkw
m(QGP\Ya
public Utility() :0,q>w
{ ( zQ)EHRD
[:gPp)f,
v3|-eWet^
} ;-p1z% u
SH>L3@Za
//线程睡眠 M,]C(f>
public static void sleep(int nSecond) 3R(GO.n=]
{ 8hWBTUN
try{ } DY{>D>
Thread.sleep(nSecond); `>CHE'_
} fl| 8#\r
catch(Exception e) m1@ste;$W
{ dz fR ^Gv
e.printStackTrace (); TWF6YAQm
} QC7Ceeh]4
} bJc<FL<E
ySP1,xq
//日志 L/Cp\|~ O
public static void log(String sMsg) g_lj/u]P
{ "?Dov/+Q.
System.err.println(sMsg); .kpL?_
} l`9<mL
VW^6qf/,
ConXP\M-
public static void log(int sMsg) y,{=*2Yt
{ _@I8B
System.err.println(sMsg); +2%ih!
} lSv?!2
} 2E~WcB
DBDHe-1[+
oBZ\mk L
/* Pw`26mB
**TestMethod.java O@;;GJ
*/ =zw=Jp
package NetFox; ~jdvxoX-
a12Q/K
m0xL'g6F
public class TestMethod { 6*`KC)a
x] [/9e
u6o:~=WwM
public TestMethod() RlH|G
{ ///xx/weblogic60b2_win.exe *?|LE C
try{ \]Nlka
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); VC%{qal;q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~R7F[R
SiteFileFetch fileFetch = new SiteFileFetch(bean); $OI 6^
fileFetch.start(); hdky:2^3
} [J0f:&7\
catch(Exception e){e.printStackTrace ();} Ewjzm,2
N{L'Q0!
H&K(,4u^
} i}cqV B?r
]dzBm!u
#CKPNk c
public static void main(String[] args) s Xyc _3N
{ P%?|V_m
new TestMethod(); [ kI|Thx
} sT.;*3{
} npsDy&
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