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)); A'QGTT
} Wx)U<:^e
for(int i=0;i<nEndPos.length-1;i++) fR%1FXpK&
{ qK vr*xlC
nEndPos = nStartPos[i+1]; _JTxm>
} uo'31V0
nEndPos[nEndPos.length-1] = nFileLength; S5u#g`I]
} poYAiq_3T
} `{lAhZ5
Guw|00w,Q$
,]_(-tyN|
//启动子线程 v#]v,C-*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; EQ63VF
for(int i=0;i<nStartPos.length;i++) E+ 3yN\X(
{ <-B"|u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]Bd3d%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |EV\a[
nStartPos,nEndPos,i); !FO^:V<|5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "=\_++
fileSplitterFetch.start(); 6eYf2sZ;J
} =l2Dm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uV}WSoq[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0O,T=z[+>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oA;Ty7s
nEndPos = " + nFileLength); ^h6$>n5
// fileSplitterFetch[nPos.length-1].start(); W({TC
j-`X_8W
~J>gVg%66
//等待子线程结束 =Cy>$/H64
//int count = 0; tK|9qs<%
//是否结束while循环 t)gi.Ed1"L
boolean breakWhile = false; yC 7Vb P
QK!:q{
lAn+gDP
while(!bStop) Q|= Q]$d
{ G9n /S=R?
write_nPos(); =PFR{=F
Utility.sleep(500); nOal7BNN
breakWhile = true; b?]ly(
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ezr\T
for(int i=0;i<nStartPos.length;i++) 5u|=;Hz*)
{ u@Cf*VPK
if(!fileSplitterFetch.bDownOver) 2@R8P~^W
{ fQW_YQsb
breakWhile = false; IFrb}yH
break; GtM( Y
} 7}'A)C>J;
} od}EM_
if(breakWhile) vf'cx:m
break; OVUs]uK
Xm8Z+}i
I51oG:6fR?
//count++; J(EaE2
//if(count>4) X(y
// siteStop(); YF! &*6m
} JU'WiR bcb
d]7|v r]
tSb?]J
System.err.println("文件下载结束！"); uqa4&2(I=j
} UROj9COv
catch(Exception e){e.printStackTrace ();} ?H[5O+P[
} 8{G?92 {rN
t$H':l0
pdi=6<?bd
//获得文件长度 6/[Z178m
public long getFileSize() Rct"\{V')n
{ T1(j l)
int nFileLength = -1; &8]#RQy{f
try{ UEEBWzH
URL url = new URL(siteInfoBean.getSSiteURL()); 7bonOt Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X%a;i6pq
httpConnection.setRequestProperty("User-Agent","NetFox"); b$?Xn{Y
.lvI8Jf~X
b$v[@"1
int responseCode=httpConnection.getResponseCode(); ntj`+7mw
if(responseCode>=400) =|E 09
{ \m=-8KpU
processErrorCode(responseCode); A \MfF
return -2; //-2 represent access is error ` /I bWu
} !f\?c7
Gpdv]SON{
dNUR)X#e
String sHeader; vXyuEEe
&\1'1`N1
\-Iny=$
for(int i=1;;i++) Q(IJD4
{ R%b*EBZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &r'{(O8$N
//Utility.log(in.readLine()); I%}L@fZ
sHeader=httpConnection.getHeaderFieldKey(i); <AI>8j6#B
if(sHeader!=null) cQ(}^KO
{ -XBKOybHBO
if(sHeader.equals("Content-Length")) |;A9A's
{ (]3ERPn#y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Hs"% S
break; NqJ<!q)
} 3z,v#2
} _{6,.TN
else ~LawF_]6
break; I!fB1aq-
} cq*p9c
} _m9~*
catch(IOException e){e.printStackTrace ();} 2Vp>"
catch(Exception e){e.printStackTrace ();} X,RT<GNNb
(TEo_BW|+
87^:<\pp
Utility.log(nFileLength); \npz.g^c_
W\it+/
;".z[l*
return nFileLength; klgv{_b
} n$.1Wk"
gB]C&Q
6Xdtr
//保存下载信息（文件指针位置） d?:`n9`
private void write_nPos() r0F_;
{ aGPqh,<QD
try{ Q0V^PDF
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0jR){G9+
output.writeInt(nStartPos.length); T>#TDMU#Fm
for(int i=0;i<nStartPos.length;i++) w$gSj/
{ paW'R+Rck
// output.writeLong(nPos); N0=-7wMk(Z
output.writeLong(fileSplitterFetch.nStartPos); CE~r4
output.writeLong(fileSplitterFetch.nEndPos); f%2%T'Q
} hzaLx8L
output.close(); :3*`IB !
} )fNGB]%
catch(IOException e){e.printStackTrace ();} q}>M& *
catch(Exception e){e.printStackTrace ();} 3YR* ^
} 6#<Ir @z
c}\ 'x5:o
U?8i'5)
//读取保存的下载信息（文件指针位置） $"Afy)Ir
private void read_nPos() -NAmu97V}
{ ;K3d' U
try{ }%eDEM
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &oA~ Tx
int nCount = input.readInt(); k_]\(myq
nStartPos = new long[nCount]; 5B%w]n
nEndPos = new long[nCount]; GGCqtA^@7d
for(int i=0;i<nStartPos.length;i++) :I2H&,JT
{ 1|W2s\
nStartPos = input.readLong(); GF&_~48GD
nEndPos = input.readLong(); j*XjY[
} >f>V5L%1
input.close(); StEQ -k
} !?jK1{E3
catch(IOException e){e.printStackTrace ();} +<&E3Or
catch(Exception e){e.printStackTrace ();} nt7|f,_J
} ;:P7}v fz!
>GgE,h
bn$)f6%
private void processErrorCode(int nErrorCode) ,ohmc\*J
{ 9+}cE**=d
System.err.println("Error Code : " + nErrorCode); ri:,q/-
} '}_=kp'X
)&>L !,z
q$F)!&
//停止文件下载 (}G!np
public void siteStop() Ddb-@YD&+0
{ ?fV?|ZGZI
bStop = true; {o( * f
for(int i=0;i<nStartPos.length;i++) G(3;;F7"
fileSplitterFetch.splitterStop(); )`^ /(YG
byafb+x
kL|\wci
} rR\;G2p)
} Hj2<ZL
//负责部分文件的抓取 Hoj8okP
**FileSplitterFetch.java xWDR726
*/ fTcY"A,2
package NetFox; -OWZ6#v(
#*^e,FF<
\Dfm(R
import java.io.*; cM3jnim
import java.net.*; 0*/kGvw`i
+,z)#
$%=G[/i'
public class FileSplitterFetch extends Thread { / $_M@>
tj[c#@[B
Apmw6cc
String sURL; //File URL K U$`!h
long nStartPos; //File Snippet Start Position /HZv
long nEndPos; //File Snippet End Position RpYcD
int nThreadID; //Thread's ID T<P0T<
boolean bDownOver = false; //Downing is over ]w!0u2K<Q\
boolean bStop = false; //Stop identical wqP2Gw7jh6
FileAccessI fileAccessI = null; //File Access interface >VP5vkv=
b:1 L@8s;
/[%w*v*'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2L:$aZ
{ `^x9(i/NE
this.sURL = sURL; )&:L'N
this.nStartPos = nStart; Jld\8=
this.nEndPos = nEnd; BKay*!'PX
nThreadID = id; ~ltg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `]jqQr97
} o5SQ1;`
myIe_k,F
W&YU^&`Yr
public void run() _lX8K:C(
{ ALXTR%f
while(nStartPos < nEndPos && !bStop) TdFT];:
{ b1xpz1
&))\2pl
0elxA8Z~e
try{ wx*1*KZ
URL url = new URL(sURL); <!F3s`7~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JaI Kjn
httpConnection.setRequestProperty("User-Agent","NetFox"); aBxiK[[`
String sProperty = "bytes="+nStartPos+"-"; ]ENK8bW
httpConnection.setRequestProperty("RANGE",sProperty); s7l23*Czl
Utility.log(sProperty); +Ofa#^5);K
<bP#H
R5(F)abi
InputStream input = httpConnection.getInputStream(); {n&Uf{
//logResponseHead(httpConnection); k3>YBf`fC
W:vr@e6
FY4T(4#
byte[] b = new byte[1024]; y^R4I_* z
int nRead; u%B&WwHG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) APq7 f8t
{ Juu+vMn1
nStartPos += fileAccessI.write(b,0,nRead); YG`?o
//if(nThreadID == 1) kAo.C Nj7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O,'#C\
} ($8t%jVWJJ
{[W(a<%bXm
+rc SL8C
Utility.log("Thread " + nThreadID + " is over!"); C6]OAUXy:F
bDownOver = true; i%F<AY\O)
//nPos = fileAccessI.write (b,0,nRead); Z!_n_Fk
} nQ-mmY>#
catch(Exception e){e.printStackTrace ();} R,,Qt TGB
} (`c G
} :h*a rT4{
Jzex]_:1~
sJU`u'w
//打印回应的头信息 Ee)xnY%(
public void logResponseHead(HttpURLConnection con) gCJIIzl%Bh
{ hqDqt"dKz
for(int i=1;;i++) 9:8|)a(1
{ EI1? GB)b
String header=con.getHeaderFieldKey(i); >;9NtoE
if(header!=null) IZrk1fh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t,<UohL|z
Utility.log(header+" : "+con.getHeaderField(header)); (>7>3
else wk @,wOt
break; [_.n$p-
} 24B<[lSK
} iKAusWj
3i=Iu0
|8U;m:AS
public void splitterStop() B<,YPS8w
{ N'?u1P4G
bStop = true; bK*~ol
} ^RNOcM|
zK;XFN#U^
e;(
} VaR/o#
E!mmLVa9
qZ+H5AG2
/* !Zjq9{t\"
**FileAccess.java GBQn_(b9I
*//文件访问(定位，写) /tj$luls5
package NetFox; z9 ($.
import java.io.*; uM S*(L_
k;KdW P
q>s`uFRg(
public class FileAccessI implements Serializable{ 27#5y_ `
D$q'FZH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RN9;kB)c
RandomAccessFile oSavedFile; RUo9eQIPD
long nPos; 1@qgF
[Qj;/
<]d LX}C)
public FileAccessI() throws IOException Hj6'pJ4
{ tSHFm-q`
this("",0); Jp~zX lu
} X.V[0$.;
VW<0Lt3
(.23rVvnT@
public FileAccessI(String sName,long nPos) throws IOException j.|U=)E
{ ,D=fFpn
oSavedFile = new RandomAccessFile(sName,"rw"); caq} &A]C
this.nPos = nPos; tef^ShF]
oSavedFile.seek(nPos); QG3&p<
} m9":{JI.w
Im?LIgt$
'EhBRU%
public synchronized int write(byte[] b,int nStart,int nLen) bF-"tm
{ VaLs`q&3>
int n = -1; 0.;}]v
try{ Q8nId<\(
oSavedFile.write(b,nStart,nLen); j6YiE~
n = nLen; ',=g;
} 5V5w:U>_z
catch(IOException e) S Xr%kndS
{ 9pD 7 f`
e.printStackTrace (); zT9JBMNE:
} j*R,m1e8
"484n/D
[V}, tO|
return n; iK;opA"
} @g-Tk
MMQ;mw=^]
v~)LO2y
} n/Dp"4H%q
/-M@[p&
,kM)7!]N
/* /X*oS&-M
**SiteInfoBean.java ajH"Jy3A
*/ N#z~
package NetFox; cP>o+-)
1vevEa$
^{yk[tHpS
public class SiteInfoBean { X[3}?,aqL
elPE%'
S::>N.y
private String sSiteURL; //Site's URL G}zZQy
private String sFilePath; //Saved File's Path pdVQ*=c?M
private String sFileName; //Saved File's Name h2q/mi5{
private int nSplitter; //Count of Splited Downloading File >Aq:K^D/3F
n.}T1q|l
x3G:(YfO
public SiteInfoBean() +[-i%b3q
{//nSplitter的缺省值为5 5Fw - d
//default value of nSplitter is 5 dK9Zg,DZL
this("","","",5); kLP0{A
} UQ?%|y*Kc
hZ$t$3
dp5cDF}l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ku&k'V
{ dA~ 3>f*b_
sSiteURL= sURL; 5K%Wa]W
sFilePath = sPath; {MBTP;{*~
sFileName = sName; }"s;\?a
this.nSplitter = nSpiltter; gFN9jM
uaPx"
^TdZ*($5
} ~N0sJ%
V!/:53
8Cx^0
public String getSSiteURL() 1Y j~fb(
{ gE7L L=x
return sSiteURL; "&+3#D >
} V9%aBkf8w
Kq6jw/T
mI1H!
public void setSSiteURL(String value) p*3; hGp6
{ E,[xUz"
sSiteURL = value; J$ut_N):N
} *ZCn8m:-+
_2ef LjXQ
Sm{>rR
public String getSFilePath() 2t#L:vY
{ 'DbMF?<.
return sFilePath; wIvo"|%
} Vm1-C<V9
A<MtKb
`)$_YZq|SR
public void setSFilePath(String value) y'C-[nk
{ @z`@f"l
sFilePath = value; JK_OZ
} ))h6~1`
dl]#
Yl cbW0'c
public String getSFileName() V*[b}Xew
{ afG{lWE)
return sFileName; (g!p>m!Z
} UK[v6".^h
GIwh@4;
clO,}Ph>
public void setSFileName(String value) uZjC c M
{ vb{i
sFileName = value; 30j|D3-
} ?=Pd
vw>jJ
n$L51#'
public int getNSplitter() @ EuFJ=h
{ mu]as: ~
return nSplitter; (=x"Y{%
} D@ek9ARAq
E>jh"|f:{
a}yXC<}$
public void setNSplitter(int nCount) g=@_Z"
{ >pL2*O^{9
nSplitter = nCount; YPDf Y<?v
} v6(E3)J7
} 256LHY|6
y2L#:[8
}ut]\]b
/* xl9aV\W
**Utility.java K,ej%Vtz
*/ sy* y\5yJ
package NetFox; \K2*Q&>
$^/0<i$
<i\A_qqc/
public class Utility { C@\{ehG
V<Z'(UI
-T@`hk`
public Utility() ~EiH-z4U
{ n||A" @b\
N3BL3:@O
8,T4lb<<
} s54nF\3V
UPU+ver
//线程睡眠 2!1.E5.I
public static void sleep(int nSecond) OTWkUB{
{ KxGX\
try{ \ gwXH
Thread.sleep(nSecond); J97R0
} koG{ |elgB
catch(Exception e) ]$-cMX
{ w&h2y4
e.printStackTrace (); &7mW9]
} .1 )RW5|c
} ;zTuKex~
Ol/\t
//日志 6aO2:|:yP
public static void log(String sMsg) )EM7,xMz
{ }CL"S_>1
System.err.println(sMsg); cV K7
} |H}sYp
<Q< AwP
gApoX0nrv
public static void log(int sMsg) e'*HS7g
{ Lz9#A.
System.err.println(sMsg); M6|I6M<
} S:Q! "U
} cc=gCE
@ T;L$x
9W7#u}Z
/* GV|9H]_,I
**TestMethod.java +%>:0mT
*/ *O$CaAr\s
package NetFox; IakKi4(
7Ey#u4Q
D87|q4
public class TestMethod { K/_9f'^
cR{>IH4^
<lxD}DH=
public TestMethod() p0p4Xh1e
{ ///xx/weblogic60b2_win.exe Z,7R;,qX
try{ L6P1L)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '(+<UpG_Q}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?^#lWx q
SiteFileFetch fileFetch = new SiteFileFetch(bean); @DAF 6ygs
fileFetch.start(); ~ AQp|
} 9W`Frx'h1
catch(Exception e){e.printStackTrace ();} H4-qB Z'
hqSJ(gs{
M[5[N{
} eLD?jTi'
f7de'^t9
B@v\eF;
public static void main(String[] args) R\Z:n*
{ &F$:Q:* *
new TestMethod(); 1t[j"CG(o
} g&/p*c_
} ZUXr!v/R:1
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