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)); e{ce \
} EFb1Y{u^\!
for(int i=0;i<nEndPos.length-1;i++) ,a:!"Z^f
{ \S[7-:Lu^
nEndPos = nStartPos[i+1]; E>/kNl
} .L,xqd[zC
nEndPos[nEndPos.length-1] = nFileLength; N36<EHq
} S,K'y?6
} ^-s'Ad3
i.eu$~F
U_/sY9gz(
//启动子线程 7^{M:kYC!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $6W o$c%
for(int i=0;i<nStartPos.length;i++) o%!8t_1mR
{ P1<Y7+n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6`KAl rH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k`LoRqF
nStartPos,nEndPos,i); W?a{3B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j@JhxCe1+R
fileSplitterFetch.start(); ZnX]Q+w
} *W'F6Hpu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a3&&7n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2"31k2H[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y"|QY!fK
nEndPos = " + nFileLength); <<43'N+
// fileSplitterFetch[nPos.length-1].start(); }y<p_dZI
#=tWjInm
&3 QdQn,
//等待子线程结束 QJBzv|
//int count = 0; F9hh- "(Z
//是否结束while循环 E0;KTcZi
boolean breakWhile = false; kC=e>v
orGNza"A
6$1dd#
while(!bStop) ohK_~
{ >^cP]gGY
write_nPos(); %SV5PO@
Utility.sleep(500); A!([k}@=j
breakWhile = true; ;Up'+[Vj'C
~m ,xG
ZI'MfkEZ*
for(int i=0;i<nStartPos.length;i++) A]fN~PR
{ 7j9:s>D
if(!fileSplitterFetch.bDownOver) Yx- 2ux
{ 0mJvoz\j8
breakWhile = false; K;%P_f/KJP
break; E7A psi4]
} d(.e%[`
} Y{6vW-z_<
if(breakWhile) _l?InNv
break; (!-gX"<b
-E6#G[JJ
(1~d/u?2\
//count++; SZO$#
//if(count>4) 8MHYk>O~{G
// siteStop(); H4s^&--
} =0te.io)3O
K[tQ>C@s2
W|IMnK-
System.err.println("文件下载结束！"); %LeQpbyOR
} ' `0kW_'
catch(Exception e){e.printStackTrace ();} Vej [wY-c
} `Yk~2t"V
#cB=](N
VO_! +
//获得文件长度 2V6=F[T
public long getFileSize() c/l%:!A
{ LRF_w)^['
int nFileLength = -1; X<\E 'v`~
try{ !PQ%h/ix
URL url = new URL(siteInfoBean.getSSiteURL()); >]6f!;Rt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :n'$Txf
httpConnection.setRequestProperty("User-Agent","NetFox"); :%[=v(G[
`6`p~
#fq%903=
int responseCode=httpConnection.getResponseCode(); dGxk ql
if(responseCode>=400) U(lcQC`$
{ J~=bW\^I
processErrorCode(responseCode); +_.k\CRms
return -2; //-2 represent access is error :}QBrd
} BCDmce`=l
$XBn:0U
tUS)1*{_
String sHeader; ]V|rOtxb
3[R<JrO
H .F-mm
for(int i=1;;i++) zV)(i<Q
{ K gN=b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RrFq"
//Utility.log(in.readLine()); Rne#z2Ok
sHeader=httpConnection.getHeaderFieldKey(i); D?+\"lI
if(sHeader!=null) ~SI`%^L
{ !VaKq_W
if(sHeader.equals("Content-Length")) 'q158x
{ F.zx]][JV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _|f1q
break; qOA+ao
} K U 2LJ_~Y
} )?5027^
else kEQ1&9
break; _?j66-( Q
} vNMndo!
} U3Fa.bC6}
catch(IOException e){e.printStackTrace ();} 8Ld`$_E
catch(Exception e){e.printStackTrace ();} jZjWz1+
o!R.QI^2VT
,g69?w
Utility.log(nFileLength); r[doN{%
t=,ZR}M1`
b3/@$x<
return nFileLength; #@ClhpLD
} ]><K8N3Z
oRf.34
zD#$]?@ b
//保存下载信息（文件指针位置） tcDWx:Q
private void write_nPos() {e'P*j
{ se|>P=/
try{ mf~JolucJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); j,DF' h
output.writeInt(nStartPos.length); <x QvS^|[
for(int i=0;i<nStartPos.length;i++) JD`IPQb~E
{ l#%qF Db
// output.writeLong(nPos); !,Ou:E?Bb
output.writeLong(fileSplitterFetch.nStartPos); sj9j47y
output.writeLong(fileSplitterFetch.nEndPos); / @v V^!#1
} /"(`oe<
output.close(); =`MxgK +
} gxKL yZO!
catch(IOException e){e.printStackTrace ();} tTjadnX
catch(Exception e){e.printStackTrace ();} x;^DlyyYU
} ^sF/-/ {?U
=3h?!$#?
2XX-
//读取保存的下载信息（文件指针位置） d4ga6N3'
private void read_nPos() _i3?;Fds
{ FTF`-}Hz
try{ Mb!b0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); COc,
int nCount = input.readInt(); VyMFALSe]h
nStartPos = new long[nCount]; RJ\'"XQ
nEndPos = new long[nCount]; o+],L_Ab
for(int i=0;i<nStartPos.length;i++) <<FBT`Y[
{ w@![rH6~F
nStartPos = input.readLong(); +YJpVxYmZ
nEndPos = input.readLong(); g=gM}`X%
} WMw|lV r
input.close(); .4[\%r\i
} s![Di
catch(IOException e){e.printStackTrace ();} [ML|,kq!
catch(Exception e){e.printStackTrace ();} #+"1">l
} 3wYhDxY1
[PIh^DhK
]/#3 P
private void processErrorCode(int nErrorCode) *Cj<Vy
{ rq#\x{l
System.err.println("Error Code : " + nErrorCode); ,qK'!
} [mcER4]}
e"d-$$'e
RM3"8J
//停止文件下载 <#ng"1J
public void siteStop() WvoJ^{\4N*
{ : GdLr
bStop = true; 9Ro7xSeD
for(int i=0;i<nStartPos.length;i++) O}-+o1
fileSplitterFetch.splitterStop(); ?mp}_x#=
,%T sfB
J1u&Ga
} B9: i.rQ
} BhzcimC)
//负责部分文件的抓取 LOEiV
**FileSplitterFetch.java 3E-dhSz:i
*/ 4n0Iw I
package NetFox; gQYs,
;S?ei>Q
ROr|n]aJj
import java.io.*; K2qKkV@
import java.net.*; {+^&7JX
ZK4d;oa",
l+#uQo6cqQ
public class FileSplitterFetch extends Thread { >sGiDK @
v;nnr0;
r'<!wp@
String sURL; //File URL 8dLK5"_3
long nStartPos; //File Snippet Start Position _Wtwh0[r*
long nEndPos; //File Snippet End Position gX~lYdA
int nThreadID; //Thread's ID ?&JKq^9\I
boolean bDownOver = false; //Downing is over `sLD>@m
boolean bStop = false; //Stop identical $}t;c62
FileAccessI fileAccessI = null; //File Access interface XD%GNZ
Q%QIr
?$6(@>`f&t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =eQ'^3a
{ YJF|J2u
this.sURL = sURL; /^9=2~b
this.nStartPos = nStart; ?/fC"MJq?
this.nEndPos = nEnd; ,R}9n@JI^Y
nThreadID = id; ncpNesB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 QT4&Ix,4T1
} sdBB(
8^puC
2f5YkmGc";
public void run() f&I5bPS7}
{ iBk1QRdn
while(nStartPos < nEndPos && !bStop) #'5{ ?Cb
{ 629ogJo8
&3|l4R\
PQrc#dfc|
try{ "XLFw;o
URL url = new URL(sURL); 1b<[/g9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t+#vcg,G
httpConnection.setRequestProperty("User-Agent","NetFox"); mq+x=
String sProperty = "bytes="+nStartPos+"-"; moCR64n
httpConnection.setRequestProperty("RANGE",sProperty); Eih6?Lpu
Utility.log(sProperty); fwi -
p^s:s-"f\
pHKc9VC
InputStream input = httpConnection.getInputStream(); [ZL<Q
//logResponseHead(httpConnection); FK@Gd)(
Z3f}'vr
V*W H
byte[] b = new byte[1024]; t{e}3}LEd
int nRead; m U= 3w
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Pp.]/;
{ V6&6I
nStartPos += fileAccessI.write(b,0,nRead); SM4'3d&mf
//if(nThreadID == 1) F{E`MK~f_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y?UB?2VN
} P1&Irwb`
Yo\%53w/
HfEl TC:3f
Utility.log("Thread " + nThreadID + " is over!"); Zfd `Fu
bDownOver = true; r`sG!
//nPos = fileAccessI.write (b,0,nRead); WO*dO9O
} kBtzJ#j B
catch(Exception e){e.printStackTrace ();} hX:yn:P~
} |?v+8QL,;t
} [*g'Y;W
h>A~yDT[
!O4)YM
//打印回应的头信息 h#Z~x
public void logResponseHead(HttpURLConnection con) 1aezlDc*
{ U.1&'U*
for(int i=1;;i++) Y?%=6S
{ 'jYKfq~_cJ
String header=con.getHeaderFieldKey(i); 'M fVZho{
if(header!=null) %?J-0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @DKph!cr
Utility.log(header+" : "+con.getHeaderField(header)); +A1xqOB
else Fnuheb'&m
break; $\L=RU!c}
} ctR^"'u
} !Y*O0_
EME}G42KN
EJ(z]M`f
public void splitterStop() ,Y@4d79
{ sqO$ka{
bStop = true; Kc`#~-`,(
} [x0*x~1B
VP^{-mDph
HBZtg
} eIbz`|%3
#KDN
ue -a/a
/* ,D'bIk
**FileAccess.java 2 ;Q|h$n
*//文件访问(定位，写) `~1#X
package NetFox; ;oOv~YB7H
import java.io.*; 1%7zCM0s
{"_V,HmEF+
.K+5k`kd
public class FileAccessI implements Serializable{ ,S1'SCwVdJ
Ll`nO;h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {<Xl57w-Q
RandomAccessFile oSavedFile; pEY zB;
long nPos; |&~);>Cq2
@1V?94T1
RA}Y$}^#'
public FileAccessI() throws IOException c1 1?Kq
{ uf`/-jY
this("",0); JQSczE3
} $HAwd6NI
O>IG7Ujl
bK|nxL
public FileAccessI(String sName,long nPos) throws IOException |^O3~!JP(>
{ v&xhS yZ
oSavedFile = new RandomAccessFile(sName,"rw"); 2lxA/.f
this.nPos = nPos; [k=LX+w@
oSavedFile.seek(nPos); c
} JiGS[tR
g8]$BhRIfr
V# JuNJ
public synchronized int write(byte[] b,int nStart,int nLen) -IL' (vx
{ [L?WM>]%
int n = -1; I}\`l+
try{ 1+Bj` ACP
oSavedFile.write(b,nStart,nLen); ]"i^VVw
n = nLen; KXcE@q9
} muKjeg'b
catch(IOException e) 7qg. :h
{ Jg@eGs\*
e.printStackTrace (); 20)8e!jP
} RY~mQ
8e_9u@p+w
|qb-iXW=
return n; LP}j0)n
} '^BTa6W}m
B &)wJG
~\Udl
} w=ZK=@
$3(E0\#O
CMYkxU
/* V4|l7
**SiteInfoBean.java k'K 1zUBj
*/ W 6CNMI]
package NetFox; ZV`o:Gd
$WbfRyXi7'
ExSy/^4f
public class SiteInfoBean { sB<y(}u
xOc&n0}%
U zMIm
private String sSiteURL; //Site's URL hFDo{yI
private String sFilePath; //Saved File's Path `YK#m4gc
private String sFileName; //Saved File's Name / KxZ+Ww>v
private int nSplitter; //Count of Splited Downloading File (&qjY I
3E;<aCG?
bYy7Ul6]
public SiteInfoBean() `^ uX`M/
{//nSplitter的缺省值为5 @BqSu|'Du,
//default value of nSplitter is 5 Wq*W+7=.
this("","","",5); &=laZxe
} v;IuB
YJBf~0r
J\\o#-H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u]Dds;~"b
{ ?yAjxoE~?
sSiteURL= sURL; +'9eo%3O
sFilePath = sPath; Q5tx\GE
sFileName = sName; e",0Er FT
this.nSplitter = nSpiltter; P>ZIP* Gr
r~T3Ieb
q%MLj./?[
} rTM0[2N
jUy$aGX
G!w?\-
public String getSSiteURL() B0:/7Ld$Ml
{ /` 4B-Y4M4
return sSiteURL; [HQ Bx`3TS
} q%k _C0
HH'5kE0;d
_u8d`7$*%
public void setSSiteURL(String value) ,98`tB0
{ &BQ%df<y\
sSiteURL = value; }B2qtb3
} jW_FaPW(p
pc/]t^]p
;.b^A
public String getSFilePath() :faB7wduW;
{ !!UQ,yU
return sFilePath; o'p[G]NQ1o
} "QCViR
1<3!
!<j)D_
public void setSFilePath(String value) Q)}z$h55
{ ?\![W5uuXG
sFilePath = value; |iB svI:
} F9C3i
K!_''Fg
y,=TB[d#
public String getSFileName() V2_I=]p_
{ jd?NN:7
return sFileName; -XARew
} ~3s\Q%
z+%74O"c
UJ6zgsD1b?
public void setSFileName(String value) M[,G#GO
{ Z;nUS,?om
sFileName = value; P0XVR_TJf
} hZNAI
HVK./yqy
T&~7*j(|e
public int getNSplitter() ~TfQuIvQB
{ 3eP7vy
return nSplitter; ,Frdi>7 ~
} >PMLjXK
R3Ka^l8R|
TkSeDP
public void setNSplitter(int nCount) 6b9&V`
{ *q |3QHZ
nSplitter = nCount; = ~^
} \]+57^8r
} (GI]Uyn
/yS/*ET8
;(,1pi7|
/* 2%(RB4+
**Utility.java 26<Wg7/,
*/ A%c)=(,
package NetFox; Y;6%pm$
58H%#3Fy
*QT|J6ng
public class Utility { JOm6Zc
' 5%`[&
Jh)K0>R
public Utility() dT*8I0\+
{ K{x FhdW
'4}c1F1T_
&33.mdBH
} eq#x~O4
DTR/.Nr'K
//线程睡眠 Zc9j_.?*
public static void sleep(int nSecond) 4]/i0\Vbam
{ =ap6IVR
try{ Nu%:7
Thread.sleep(nSecond); %"> Oy&3
} GxR, 3
catch(Exception e) t[-0/-4
{ (66DKG
e.printStackTrace (); Udh!%QP%[w
} wuQ>|\Zs
} _p`@/[(|
'o*:~n
//日志 G]- wN7G
public static void log(String sMsg) q T pvz
{ }&mFpc
System.err.println(sMsg); ;dh8|ujh
} Jqt&TqX@s
*(4TasQu
k v}<u
public static void log(int sMsg) |_P-
{ Dxwv\+7]
System.err.println(sMsg); 9C{\=?e;
} EdPN=
} l< y9ue=
d$G<g78D
_>moza
/* T"GuE[?a
**TestMethod.java `=0J:
*/ CY4_=
package NetFox; !j3V'XU#Zn
f2#9E+IQ
BU="BB/[
public class TestMethod { /~LXY<-(
w$5N6
#NVqS5
public TestMethod() m7XJe[O
{ ///xx/weblogic60b2_win.exe /Jc?;@{
try{ q-.e9eoc\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xmDX1sL**
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K+` Vn
SiteFileFetch fileFetch = new SiteFileFetch(bean); lbES9o5
fileFetch.start(); Te8BFcJG
} FNDLqf!j
catch(Exception e){e.printStackTrace ();} %(-YOTDr
/)i)wxi
~?}/L'q!b
} <(JsB'TK
fJCh
/s%I(iP4
public static void main(String[] args) oPNYCE
{ 7[-jr;v
new TestMethod(); oT5xe[{yj
} 'D-#,X C
} ED/-,>[f
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