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)); UJkg|eu
} #3maT*JY
for(int i=0;i<nEndPos.length-1;i++) 'UO,DFq[Fl
{ !Y_"q^5GG'
nEndPos = nStartPos[i+1]; iK%<0m
} tx;DMxN!W
nEndPos[nEndPos.length-1] = nFileLength; Q[i/]
} ug!DL=ZW
} JsOPI]
X ^>o/U
oo7&.HWf
//启动子线程 ~uRG~,{rH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <by}/lF0
for(int i=0;i<nStartPos.length;i++) o[*</A }
{ '2=u<a B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O4FW/)gq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), '>> IMF
nStartPos,nEndPos,i); %7BVJJp2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QZk:G+$
fileSplitterFetch.start(); vTYI ez`g
} yv4ki5u`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +]Of f^s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]B0>r^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FQ?,&s$Bmd
nEndPos = " + nFileLength); j[YzBXd V
// fileSplitterFetch[nPos.length-1].start(); Kg&{ ?&
y|b|_eE?{
B+|E|8"
//等待子线程结束 p8y_uNQE
//int count = 0; /zn|?Y[
//是否结束while循环 PPT"?lt*&
boolean breakWhile = false; )NZ6!3[@
%>'2E!%
/h%<e
while(!bStop) v'*Q[ ('
{ k%#`{#ni
write_nPos(); VtF^; f
Utility.sleep(500); }(O/y-
breakWhile = true; !_s|h@
hNUAwTH6
^[XxE Lx
for(int i=0;i<nStartPos.length;i++) 5gW`;Cdbyc
{ hb9X<N+p
if(!fileSplitterFetch.bDownOver) u814ZN}
{ %*P59%
breakWhile = false; o#E 3{zM
break; mnL \c'
} 1Nx.aji
} vTjgW?9
if(breakWhile) HyXw^ +tsj
break; "!XeK|Wi
m}0US;c#f
OlhfBu)~
//count++; NAhV8
//if(count>4) ed*Cx~rT
// siteStop(); joDnjz=
} 6cSMKbgZJ
zfL$z,zgf
(,Yb]/O*
System.err.println("文件下载结束！"); H[V^wyi'z
} hNc;,13
catch(Exception e){e.printStackTrace ();} i0,{*LD%^
} noe1*2*TE
0"o<(1
,5'LbO-
//获得文件长度 oM-{)rvQd
public long getFileSize() CmRn
{ &'Qz
int nFileLength = -1; }uWJ
try{ wNDLN`,^H
URL url = new URL(siteInfoBean.getSSiteURL()); g^8dDY[%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]4\^>
httpConnection.setRequestProperty("User-Agent","NetFox"); `LH!"M
-2|D( sO
+FQ:Q+
int responseCode=httpConnection.getResponseCode(); Y32F{ z
if(responseCode>=400) ]>/YU*\
{ !`\W8JT+
processErrorCode(responseCode); Dqe)8 r
return -2; //-2 represent access is error ?LgR8/Io@5
} VgZ<T,SuW
Gk,{{:M:5
MLY19;e
String sHeader; >1a-}>r
Vj4 if@Z
$/],QD_;"
for(int i=1;;i++) !798%T
{ p+;Re2Uyg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L@S"c (
//Utility.log(in.readLine()); +%X_+9bd
sHeader=httpConnection.getHeaderFieldKey(i); 93x.b]]"
if(sHeader!=null) x@2rfs
{ ?1r@r
if(sHeader.equals("Content-Length")) 7GfgW02
{ wxsJB2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); twt Bt L
break; lf0/0KH
} Vv' e,m
} MTb}um.($
else n0U^gsD4J
break; 9~zh]deH
} BzF.KCScs
} "Na9Xea
catch(IOException e){e.printStackTrace ();} O 4N_lr~
catch(Exception e){e.printStackTrace ();} J><O 51
L;nRI.
52m^jT Sx
Utility.log(nFileLength); ?Li^XONz
]?-56c,
T =3te|fv
return nFileLength; jp8=>mk
} m<8j' [+
Jl Q%+$
yr&oJYM
//保存下载信息（文件指针位置） YC&iH>jO3
private void write_nPos() _|DP
{ %%c0UaV
try{ kBIF[.v(\
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0o At=S
output.writeInt(nStartPos.length); fj0+a0h
for(int i=0;i<nStartPos.length;i++) i0-!!
{ j6Jz
// output.writeLong(nPos); rRcfZZ~` M
output.writeLong(fileSplitterFetch.nStartPos); y;0.P?Il"
output.writeLong(fileSplitterFetch.nEndPos); '`"LX!"ZO
} -_uL;9r
output.close(); *IGxa
} =d~]*[8
catch(IOException e){e.printStackTrace ();} ifTVTd7O
catch(Exception e){e.printStackTrace ();} |rdG+>
} &-<"HW
wuzz Wq
}K~JM1(26
//读取保存的下载信息（文件指针位置） <B`}18x
private void read_nPos() {tOuKnnS
{ J}jK_
try{ 6xdu}l=%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "1%<IqpU+
int nCount = input.readInt(); "x\3`Qk
nStartPos = new long[nCount]; _QvyFKAM
nEndPos = new long[nCount]; gK(E0p"
for(int i=0;i<nStartPos.length;i++) XYod>[.x
{ *Q!b%DIa$
nStartPos = input.readLong(); hNDhee`%6
nEndPos = input.readLong(); (N;Jw^C@
} (&x~pv"+
input.close(); ?[RG8,B
} vR,HCI
catch(IOException e){e.printStackTrace ();} QIi*'21a+
catch(Exception e){e.printStackTrace ();} pC8(>gV<h
} enG6T
YL){o$-N"J
G8u8&|
private void processErrorCode(int nErrorCode) ^l$(-#'y
{ YD.3FTNGC
System.err.println("Error Code : " + nErrorCode); |\QR9>
} O b8[P=
3;>(W
wB9IP{Pf
//停止文件下载 L%B+V;<h3
public void siteStop() =v:_N.Fh-c
{ 07(E/A]
bStop = true; ++&F5'?g
for(int i=0;i<nStartPos.length;i++) $)n{}8^
fileSplitterFetch.splitterStop(); Maa5a
]XPGlM
d[~c-G6
} |o!<@/iH=
} X[@>1tl
//负责部分文件的抓取 *uEU9fX
**FileSplitterFetch.java S BFhC
*/ Y\+^\`Tqu
package NetFox; _ <>+Dk&
cYbO)?mC_
+D h=D*
import java.io.*; I]k'0LG*^
import java.net.*; {_q2kk
46XB6z01
N23s{S t
public class FileSplitterFetch extends Thread { }rO4b>J
MO _9Yi
7PQedZ<\
String sURL; //File URL @=;6:akz`
long nStartPos; //File Snippet Start Position 2Cr+Z(f
long nEndPos; //File Snippet End Position W!X#:UM)
int nThreadID; //Thread's ID cU{LyZp
boolean bDownOver = false; //Downing is over +Og O<P
boolean bStop = false; //Stop identical 20fCWVw}?}
FileAccessI fileAccessI = null; //File Access interface fLD9RZ8_
_eO]awsA
[w{ZP4d>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException whLske-
{ qh2.N}lW
this.sURL = sURL; Ey6K@@%
this.nStartPos = nStart; %1=W#jz
this.nEndPos = nEnd; 2X*epU_1h
nThreadID = id; xDQ$Ui.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2f:'~ P56
} ItRGq
'R'>`?Nh
4U6{E#
public void run() RtIc:ym
{ 9723f1&Vd
while(nStartPos < nEndPos && !bStop) {>+$u"*
{ 5vpf;
RU{}qPs?
1B1d>V$*
try{ RF;N]A?*
URL url = new URL(sURL); yjSN;3t71
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `2@-'/$\I|
httpConnection.setRequestProperty("User-Agent","NetFox"); xS(sRx+A
String sProperty = "bytes="+nStartPos+"-"; TWs|lhC7!
httpConnection.setRequestProperty("RANGE",sProperty); yq<YGNy!
Utility.log(sProperty); QqwXFk
#ERn 8k
fk"{G>&8
InputStream input = httpConnection.getInputStream(); Ja (/ym^
//logResponseHead(httpConnection); ScTqnY$v
'sA&Pm
djSN{>S
byte[] b = new byte[1024]; Olno9_'
int nRead; 4/h2_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Gt1Up~\s
{ t]` 2f3UO
nStartPos += fileAccessI.write(b,0,nRead); q@\_q!
//if(nThreadID == 1) sbs"26IE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xv*mK1e
} gRFC n6Q
iM9563v
V\G>e{
Utility.log("Thread " + nThreadID + " is over!"); A]J^{h0k
bDownOver = true; hD,-!R
//nPos = fileAccessI.write (b,0,nRead); AzV5Re8M
} wH`@r?&
catch(Exception e){e.printStackTrace ();} n;=A'g|Q
} e7qT;
} t/$xzsoJZr
3Yf$WE8#l
gON6jnDO
//打印回应的头信息 "/"qg
public void logResponseHead(HttpURLConnection con) |`okIqp
{ 4ku/3/6
for(int i=1;;i++) p']AXJ`Z
{ ]S:@=9JB'
String header=con.getHeaderFieldKey(i); H|!s.
if(header!=null) v]J# SlF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7 dzE"m
Utility.log(header+" : "+con.getHeaderField(header)); \%C[l
else yjr@v!o
break; 4tC_W!?$t
} g}D$`Nx:
} K@i*Nl
0l##M06>
aE%VH ;?
public void splitterStop() H|Nw)*.
{ "5YdmBy
bStop = true; }ot _k-
} O`u!P\
bPOx~ CMh
K$ &wO.
} gP<_DEd^`
,YY#ed&l
xHGoCFB
/* 3dbf!
**FileAccess.java VZ,T`8"
*//文件访问(定位，写) &8pXkD#A
package NetFox; 9,W-KM
import java.io.*; % n{W
${+.1"/[
vhHMxOZ;
public class FileAccessI implements Serializable{ n1t(ns|
Q*8-d9C
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hG@ys5
RandomAccessFile oSavedFile; `[KhG)Y7t
long nPos; TH|hrL;:8
e!yw"Cf*
caP
public FileAccessI() throws IOException |z'?3?,~
{ j+9 S
this("",0); R]Oy4U,f
} W'jXIO
ETOc4hMO
hkJZqUA
public FileAccessI(String sName,long nPos) throws IOException vo$66A
{ /4?`F}7)
oSavedFile = new RandomAccessFile(sName,"rw"); ]cr;PRyv
this.nPos = nPos; mc'p-orAf
oSavedFile.seek(nPos); @"!SU'*
} q(7D8xG;F
:/NN=3e
/;4MexgB%
public synchronized int write(byte[] b,int nStart,int nLen) [Mz;:/
{ {H V,2-z
int n = -1; RuZ;hnE&
try{ H1nQ.P]_
oSavedFile.write(b,nStart,nLen); 0vp I#q
n = nLen; F4Uk+|]Bu
} 3\+p1f4
catch(IOException e) GU3/s&9
{ bY~v0kg
e.printStackTrace (); 'EV *-_k
} G C'%s
IFxI>6<&
>#?: x*[
return n; d*$<%J
} L_mqC(vn
G 7]wg>*
.Qt3!ek
} gN(hv.nQ
<gLtX[v!CL
05B+WJ1
/* m;f?}z_\$
**SiteInfoBean.java }qhK.e
*/ 5$U>M
package NetFox; YSo7~^1W"
#&83;uys
.,Qnn}:l
public class SiteInfoBean { ^gzNP#A<'o
"PaGDhS
fR4l4 GU?)
private String sSiteURL; //Site's URL M7R&J'SAY
private String sFilePath; //Saved File's Path t3$gwO$
private String sFileName; //Saved File's Name JF%=Bc$C
private int nSplitter; //Count of Splited Downloading File 3|Sy'J0'K
,,@`l\Pgd
k{jw%a<Sc
public SiteInfoBean() cl{W]4*$
{//nSplitter的缺省值为5 k_<{j0z.
//default value of nSplitter is 5 X3{1DY3@u
this("","","",5); i8_x1=A
} U!:!]DX(
oxQID
%:KV2GP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vQmackY
{ !`[I>:Ex
sSiteURL= sURL; 8 QF?W{NK
sFilePath = sPath; \.P}`Bpa
sFileName = sName; "jO3Y/>S
this.nSplitter = nSpiltter; @O}j:b
sLdUrD%
3C=clB9<
} Ln2C#Uf
t* vg]Yc
Nu/Qa:H_{
public String getSSiteURL() |8 2tw|<o
{ jne9=Als5
return sSiteURL; 6BU0hV
} mqk(UOK`
' P`p.5nH
KV}U{s+U8
public void setSSiteURL(String value) 19 wqDIE0
{ \h7J/es^p!
sSiteURL = value; Mp"ci+Iu
} =+}}Sv2
BrH;(*H)8
I.+)sB?5
public String getSFilePath() ClMtl59
{ *C@[5#CA2z
return sFilePath; iW1ih QX
} 8;g.3Qv
e=o{Zo?H=
mERrcYY{
public void setSFilePath(String value) h2"|tTm,a
{ %C`'>,t>
sFilePath = value; O {6gNR,*
} Eqmv`Z [_
'SU9NQS
6!%d-Z7)
public String getSFileName() `x$}~rP&)!
{ 'CX.qxF1;p
return sFileName; n22hVw
} xcZ%,7
M&djw`B
s>@#9psm
public void setSFileName(String value) 2Cd --W+=
{ 6"Lsui??
sFileName = value; ?FV7|)f
} dD^_^'i
j&[.2PW\
u1)TG"+0
public int getNSplitter() W]D`f8r9
{ {nPkb5xbW
return nSplitter; u@bOEcxK
} =F%wlzF:
YKe0:cWc
85|95P.<
public void setNSplitter(int nCount) +# RlX3P
{ !*?(Q6
nSplitter = nCount; O:,2OMB}B`
} a\&(Ua
} Ukx/jNyYv
Ztyv@z'/Z
LPapD@Z
/* t}XB|h
**Utility.java otz_nF;E
*/ we\b]
package NetFox; 2JA&{ch
%<wQ
u3M`'YCb
public class Utility { ^\vfos
zY+t,2z
BK(pJNBh
public Utility() c3zT(FgO>N
{ /m Q2;*|
}+{*, z
y'_V/w s
} RD6h=n4B
g<2lPH
//线程睡眠 r%y;8$/-
public static void sleep(int nSecond) mo|PrLV
{ 7~kpRa@\P
try{ 5mna7BCEb
Thread.sleep(nSecond); 7O8V1Tt
} /OhaERv
catch(Exception e) ]Z.<c$
{ m]0^
e.printStackTrace (); Siz!/O!'
} }_a+X
} +EST58
R0Ax$Cv{
//日志 .7pGx*WH^Y
public static void log(String sMsg) x2j/8]'o
{ <+? Y
System.err.println(sMsg); IqhICC1V-
} W>`g;[ W
RwAbIXG{0
QJM-`(
public static void log(int sMsg) PPwxk;
{ sR"zRn
System.err.println(sMsg); ( }]37
} f?=r3/AO
} 8!u/
wJ80};!
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/* ~K5Cr
**TestMethod.java )l+XDI
*/ v>#Cg\
package NetFox; N?qIpv/a.
T!u'V'Ei2
>]Mq)V9
public class TestMethod { xa87xX=a
LPEjRG,
g2g`,"T
public TestMethod() P$p@5hl
{ ///xx/weblogic60b2_win.exe TK;\_yN
try{ jd ["eI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y#]}5gJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8ivRp<9
SiteFileFetch fileFetch = new SiteFileFetch(bean); :D"@6PC]
fileFetch.start(); ;Y Dv.I
} _:wZmZU}
catch(Exception e){e.printStackTrace ();} p>k]C:h
lZ}izl
LQh^; ]^(
} t{_!Z(Rt5)
"DVt3E
25xcD1*
public static void main(String[] args) wn &$C0
{ o;ik Z*+*
new TestMethod(); :fxWz%t
} mWNR(()v
} S3R|8?|
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