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)); @PPR$4
} (VYR!(17
for(int i=0;i<nEndPos.length-1;i++) cW)Oi^q%o2
{ 3z,v#2
nEndPos = nStartPos[i+1]; lx{.H,1~
} i1qS ns
nEndPos[nEndPos.length-1] = nFileLength; tS\=<T
} T&1-eq>l
} ;".z[l*
L]k*QIn:h
Md8(`@`o
//启动子线程 Mn]}s:v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t|;%DA)fjw
for(int i=0;i<nStartPos.length;i++) |}_gA
{ Z0e-W:&;kF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wL'oImE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <1aa~duT
nStartPos,nEndPos,i); .Qd}.EG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p QluGIX0V
fileSplitterFetch.start(); 7dSh3f!
} L)q`D2|'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QTVa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {bN Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H}vn$$ O
nEndPos = " + nFileLength); XjX 2[*l
// fileSplitterFetch[nPos.length-1].start(); 5pO]vBT
~6p5H}'H1
\WWG>OUh.U
//等待子线程结束 FyCBNtCv
//int count = 0; X*0k>j
//是否结束while循环 );=Q] >
boolean breakWhile = false; I?^aCnU
R;WW f.#
J;S-+
while(!bStop) -:MmSeG7gO
{ C?,*U
write_nPos(); Gc wt7~
Utility.sleep(500); pg+b[7
breakWhile = true; UanEzx%
q$F)!&
fTBVvY4(
for(int i=0;i<nStartPos.length;i++) /w0sj`;"
{ iecWa:('
if(!fileSplitterFetch.bDownOver) <P-$RX
{ E-^2"j>o
breakWhile = false; f_rp<R>Uu
break; a~,Kz\Tt
} hqL+_|DW
} mB~~_]M N
if(breakWhile) 4h;4!I|
break; *,17x`1e
#G[t X6gU
rkq#7
//count++; <KX&zi<L)
//if(count>4) K U$`!h
// siteStop(); H37QgApB
} ;=a_B1"9u
Ls1B\Aw_
$C uR}g
System.err.println("文件下载结束！"); dq(E&`SzK
} D^|9/qm$
catch(Exception e){e.printStackTrace ();} Jld\8=
} >OK#n)U`
/D'M24
myIe_k,F
//获得文件长度 d*2u}1Jo8
public long getFileSize() *}w+68eO
{ A@2Bs5F
int nFileLength = -1; TcJ$[
try{ a~opE!|m
URL url = new URL(siteInfoBean.getSSiteURL()); i'=2Y9S}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !p',Za
httpConnection.setRequestProperty("User-Agent","NetFox"); b# u8\H
+Ofa#^5);K
{~'H
int responseCode=httpConnection.getResponseCode(); '#q4Bc1
if(responseCode>=400) W:vr@e6
{ 'mE^5K
processErrorCode(responseCode); e>AXXUEf
return -2; //-2 represent access is error [EOVw%R
} UV@0gdy[
~8{sA5y
"(f`U.
String sHeader; "}zt`3
^_W40/c3
MA* :<l
for(int i=1;;i++) )];aIA$
{ ?lKhzH.T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wk @,wOt
//Utility.log(in.readLine()); X{Zm9T
sHeader=httpConnection.getHeaderFieldKey(i); h/m6)m.D
if(sHeader!=null) !%[S49s
{ xaW{I7FfG
if(sHeader.equals("Content-Length")) bK*~ol
{ zk}{ dG^M:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Fr [7
break; K 1W].(-@4
} 2*AG7
} U(,.D}PG
else bRsTBp;R`I
break; v~=\H
} r\qz5G *6
} ~x]9SXD%
catch(IOException e){e.printStackTrace ();} QJBr6
catch(Exception e){e.printStackTrace ();} goZ V.,w
AK@L32-S
OH'ea5xq
Utility.log(nFileLength); Hj6'pJ4
Or+p%K}-7
{y-^~Q"z
return nFileLength; l,`!rF_
} 5v _P Oq
caq} &A]C
6v732;^
//保存下载信息（文件指针位置） ;rHO&(h-
private void write_nPos() #b)e4vwCq
{ l"pN90B4
try{ }NCL>l;q
output = new DataOutputStream(new FileOutputStream(tmpFile)); MesRa(
output.writeInt(nStartPos.length); |i7a@'0)
for(int i=0;i<nStartPos.length;i++) 8e2?tmWM
{ 57I}RMT"
// output.writeLong(nPos); TqAPAHg
output.writeLong(fileSplitterFetch.nStartPos); uGVy6,
output.writeLong(fileSplitterFetch.nEndPos); CIC[1,
} TO#Pz.)>B6
output.close(); h<l1U'Bn7
} !0}\&<8/m
catch(IOException e){e.printStackTrace ();} r4XH =
catch(Exception e){e.printStackTrace ();} =Lp7{09u
} WF2-$`x
04@cLDX8uB
E6MA?Ax&=
//读取保存的下载信息（文件指针位置） g@ith&*=h
private void read_nPos() 8Ogv9
{ CA s>AXbs
try{ b[ w;i]2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &#w=7L3AW
int nCount = input.readInt(); pPro }@@
nStartPos = new long[nCount]; 5Fw - d
nEndPos = new long[nCount]; I PCGt{B~
for(int i=0;i<nStartPos.length;i++) $jzFc!rs
{ nv/[I,nw
nStartPos = input.readLong(); i@P}{
nEndPos = input.readLong(); 5K%Wa]W
} YwDt.6(+,
input.close(); WcUJhi^\C
} b^CNVdo'
catch(IOException e){e.printStackTrace ();} Me3dpF
catch(Exception e){e.printStackTrace ();} z8_XX$Mnt
} N"7]R[*
C(?blv-vM0
nHXX\i
private void processErrorCode(int nErrorCode) :!TIK1
{ Jh/ E@}'
System.err.println("Error Code : " + nErrorCode); &(pjqV
} KLWDo%%u
pox,Im
'DbMF?<.
//停止文件下载 ssQ BSbx
public void siteStop() ~l E _L1-c
{ G;iEo4\?
bStop = true; [U{UW4
for(int i=0;i<nStartPos.length;i++) olux6RP[B
fileSplitterFetch.splitterStop(); qdD)e$XW,
9WG{p[
@* ust>7
} ?}QH=&=^
} a*dQ _
//负责部分文件的抓取 MjL)IgT
**FileSplitterFetch.java vb{i
*/ 3,X/,'
package NetFox; +>f<EPGn
@ EuFJ=h
X@2-*so<
import java.io.*; /B3R1kNf|
import java.net.*; KFRw67^
]3{0J
YPDf Y<?v
public class FileSplitterFetch extends Thread { B^ 7eoW
"\%On >
F"+o@9]
String sURL; //File URL &]6)LFm
long nStartPos; //File Snippet Start Position OW;tT=ql
long nEndPos; //File Snippet End Position /7c~nBU
int nThreadID; //Thread's ID L71!J0@a#
boolean bDownOver = false; //Downing is over ],etZ%z&
boolean bStop = false; //Stop identical El_Qk[X|A
FileAccessI fileAccessI = null; //File Access interface (?)7)5H
y^>Q/H\
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E$s/]wnr[
{ 5f'DoT
this.sURL = sURL; J97R0
this.nStartPos = nStart; +xv!$gJEj
this.nEndPos = nEnd; C]u',9,
nThreadID = id; .1 )RW5|c
fileAccessI = new FileAccessI(sName,nStartPos);//定位 UKd'+R]
} ,$*IzL~
9Ru;`
F?+3%>/A@
public void run() H;ZHqcUX
{ j-@kW'K
while(nStartPos < nEndPos && !bStop) V)M1YZV{
{ IV16d
0Wvq>R.(]7
5i6 hp;=
try{ R"Liz3Vl%
URL url = new URL(sURL); ^WYQ]@rh3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); od<b!4k~s
httpConnection.setRequestProperty("User-Agent","NetFox"); pcS+o
String sProperty = "bytes="+nStartPos+"-"; _mE^rT
httpConnection.setRequestProperty("RANGE",sProperty); \kIMDg3}
Utility.log(sProperty); z$lF)r:Bc
+%>:0mT
CJknJn3m&
InputStream input = httpConnection.getInputStream(); &[R8Q|1j
//logResponseHead(httpConnection); \{\MxXW
u+9<&)X0
$P o}
byte[] b = new byte[1024]; tq50fq'
int nRead; * A|-KKo\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .lG5=Th!
{ n| O [a6G
nStartPos += fileAccessI.write(b,0,nRead); imL_lw^?
//if(nThreadID == 1) ^H'a4G3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Tpp&
} m`?MV\^
we7c`1E
T$4P_*
Utility.log("Thread " + nThreadID + " is over!"); t/oN>mQG
bDownOver = true; ,1{Ep`
//nPos = fileAccessI.write (b,0,nRead); gYop--\14]
} x<i}_@Sn_+
catch(Exception e){e.printStackTrace ();} q6P wZ_
} &O\(;mFc
} 4pU>x$3$
9Mm!%Hu
O%!5<8Xrb
//打印回应的头信息 &xZyM@
public void logResponseHead(HttpURLConnection con) 8[%Ao/m
{ ZUXr!v/R:1
for(int i=1;;i++) U!w1AY|
{ d^ ZMS~\*
String header=con.getHeaderFieldKey(i); YA(@5CZ
if(header!=null) "I- w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n}-3o]ku
Utility.log(header+" : "+con.getHeaderField(header)); @R~5-m
else {Z;t ^:s#
break; "$HbK @]!h
} w2(guL($
} a@d=>CT$
#b0{#^S:
c>bq%}
public void splitterStop() v0*N)eqDGd
{ *DI)?
bStop = true; s$h] G[x
} _#$9 y1bd
eEc4bVQa
3+7^uR$/I4
} 1{"llD
^>4o$}
{y kYW%3s
/* JHn*->m
**FileAccess.java :bU(S<%M
*//文件访问(定位，写) X+8B!F
package NetFox; [BbutGvj
import java.io.*; Ft{[ae?4
<g8K})P
fg%&N2/(.B
public class FileAccessI implements Serializable{ i?;r7>
De *7OC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "7%:sty
RandomAccessFile oSavedFile; DLE8+NV8
long nPos; yTM{|D]$(
][PzgzG
nCg66-3A
public FileAccessI() throws IOException "T/>d%O1b
{ \~rlgxd
this("",0); 05\dl
} `<\}FS`'
CCijf]+
@# P0M--X
public FileAccessI(String sName,long nPos) throws IOException n ?[/ufl
{ wy1X\PJjH
oSavedFile = new RandomAccessFile(sName,"rw"); ~.Ik#At
this.nPos = nPos; $ls[|N:y0l
oSavedFile.seek(nPos); w [>;a.$
} k4J8O3E
%rQuBi# 1f
lkIn%=Z
public synchronized int write(byte[] b,int nStart,int nLen) I 1d0iU
{ jPvDFT^d/
int n = -1; < O*6T%;
try{ j'%4{n
oSavedFile.write(b,nStart,nLen); `WEZ"5n
n = nLen; 9D\4n
} EC&@I+'8Q
catch(IOException e) ,"-Rf<q/
{ 4S0>-?{
e.printStackTrace (); t5k!W7C
} T<yP* b2E
6Sj6i^"
mwv(j_
return n; bZ_mYyBh
} }!#gu3
p4>$z& _
xZ5M/YSyG
} 3CjL\pIC
iL{M+Ic
6Z?j AXGSq
/* bSwWszd~
**SiteInfoBean.java stl 1QO(h
*/ .Jb$l$5'w
package NetFox; 9&%fq)gS
+!-~yf#RE
DH DZ_t:
public class SiteInfoBean { inPJ2uBD\^
_?7#MWe&
9ILIEm:
private String sSiteURL; //Site's URL t-u|U(n
private String sFilePath; //Saved File's Path a>4uiFiv
private String sFileName; //Saved File's Name Z{IUy
private int nSplitter; //Count of Splited Downloading File 9n]|PEoAB
I0AJY )R
kpwt]]e*
public SiteInfoBean() !2CL1j0(
{//nSplitter的缺省值为5 T@wcHg
//default value of nSplitter is 5 WE}kTq
this("","","",5); iVtl72O
} m4k Bj*6c{
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<q)4la
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $VG*q
{ `"yxdlXA
sSiteURL= sURL; ?q`0ZuAg\<
sFilePath = sPath; z_;3H,z`
sFileName = sName; $FH18
this.nSplitter = nSpiltter; "}WJd$
4:3rc7_ 1
6q<YJ.,
} }*]B-\>
?)Nj c&G
9CGNn+~YI
public String getSSiteURL() PW(\4Q\
{ 8rZ!ia!
return sSiteURL; B@Co'DV[/]
} RT/o$$
4rK{-jvh>m
A*h{Lsx;
public void setSSiteURL(String value) h<<>3A
{ @K223?c8l
sSiteURL = value; _i_Q?w`
} }TRAw#h
+'@+x'/{^
iO/XhSD
public String getSFilePath() Eh</? Qv\
{ KAA-G2%M
return sFilePath; d9*hBm
} hD,:w%M
B3m_D"?
@4d)R
public void setSFilePath(String value) NvE}eA#
{ ;DA8B'^>
sFilePath = value; 2=0DCF;Bv
} `=+^|Y}
5hj
N/YWby=H
public String getSFileName() _8fr6tO+
{ .xzEAu;
return sFileName; 5wB =>
} ~0$NJrUy
q>f<u&
exh/CK4;
public void setSFileName(String value) .LVQx
{ -&82$mj
sFileName = value; q/3ziVd7p
} %98' @$:0
0`.^MC?
D.D$#O_n.S
public int getNSplitter() N#V.1<Y
{ VUTacA Y>L
return nSplitter; LZPuDf~/
} J]W5[)L
EcIE~qs
gM>t0)mGK
public void setNSplitter(int nCount) W)'*m-I
{ V$0dtvGvH
nSplitter = nCount; 5vo.[^ty
} kP#e((f,
} d\e7,"L*Q
wIkN9 f
Vc^HVyAx@n
/* %6Q4yk
**Utility.java a{!QOX%K
*/ f)]%.>
package NetFox; l1ZY1#%j
%1pYEHn
+% /s*EC'w
public class Utility { fQrhsuCrC
y(R? ,wa=]
Li*eGlId
public Utility() _%'},Xd.z
{ "5cM54Z0
W\1i,ew>
6y%0`!
} zf3v5Hk
2Q;9G6p
//线程睡眠 'B+ ' (f
public static void sleep(int nSecond) NM)k/?fA
{ kyR*D1N&)
try{ 0$r^C6}f
Thread.sleep(nSecond); S9HwIH\m
} iy""(c
catch(Exception e) keRE==(D
{ 0"~i^
e.printStackTrace (); 4k./(f2+
} bINvqv0v
} %s19KGpA
54zlnM$
//日志 J>d.dq>r
public static void log(String sMsg) 0M\D[mg
{ X.`~>`8
System.err.println(sMsg); ">?vir^
} 1+?N#Fh
6(PM'@i
-G6U$
public static void log(int sMsg) iR"N13
{ V|\7')Qq
System.err.println(sMsg); C]Q8:6b
} r(gXoq_w
} $1SUU F\.
8QMPY[{
Sna4wkbS
/* ;#Q%j%J
**TestMethod.java cX3lt5
*/ Sp@-p9#
package NetFox; #m={yck *
F-6c_!
(5\NB0
public class TestMethod { # W"=ry3{
QY== GfHt
o6$4/I
public TestMethod() Y))NK'B5
{ ///xx/weblogic60b2_win.exe \6\<~UX^
try{ hpU2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4*$G & TX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4[N^>qt =
SiteFileFetch fileFetch = new SiteFileFetch(bean); $ MC)}l
fileFetch.start(); 4>J
} AlJ} >u
catch(Exception e){e.printStackTrace ();} Q|@4bzi)
<_Q1k>
Z(Jt~a3o
} Kv~U6_=1O
5 (A5Y-B
fDSv?crv
public static void main(String[] args) 'F3)9&M
{ vx4+QQYP
new TestMethod(); #KO,~]k5|e
} A`R{m0A
} ZK)%l~J
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