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)); p3-sEIw}Ru
} :JOF!Q
for(int i=0;i<nEndPos.length-1;i++) wvgX5P>
{ $}jSIn=~|t
nEndPos = nStartPos[i+1]; 0h5T&U]${Y
} ;Z8K3p
nEndPos[nEndPos.length-1] = nFileLength; VfQSfNsi
} /2YI!U@A
} -dza_{&+iZ
kmuF*0Bjk
f6z[k_lLN
//启动子线程 O/FQ'o1F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; KI#hII[Q.
for(int i=0;i<nStartPos.length;i++) K/08F|]a
{ Xf.SJ8G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zIlQqyOQ8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0R; ;ou
nStartPos,nEndPos,i); (l$bA_F\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X09&S4
fileSplitterFetch.start(); :*\JJ w
} ?{+}gS^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ('>!dXA$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MN#\P1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fghJj@ES
nEndPos = " + nFileLength); ,Z3.Le"
// fileSplitterFetch[nPos.length-1].start(); "d{ |_Cf
>`t |a
[aIQ/&Y
//等待子线程结束 f):|Ad|
//int count = 0; O* 7"Q&
//是否结束while循环 uRp-yu[nt%
boolean breakWhile = false; 7H=/FT?e]
"EA%!P:d,
d^,u"Z9P
while(!bStop) UD.$C
{ g4U%(3,>D
write_nPos(); zHyM@*Gf(
Utility.sleep(500); G"C'/
breakWhile = true; o8Tt|Lxb$8
QV" |
pvcD 61,
for(int i=0;i<nStartPos.length;i++) &t`l,]PQ=6
{ qi$6y?
if(!fileSplitterFetch.bDownOver) 2r\f!m'
{ VJm).>E3k
breakWhile = false; uN'e~X6
break; ':J[KWuV
} V+DN<F-
} cE[4CCpy
if(breakWhile) X62GEqff
break; g }5lGz4
mhVSZhx|
)f,iey\-
//count++; }+,;wj~
//if(count>4) Fd0R?d
// siteStop(); O$KLQ'0"n
} l+RBe<Mq
(rvK@
1_f(;WOg
System.err.println("文件下载结束！"); >12phLu
} l&[x)W
catch(Exception e){e.printStackTrace ();} Ij4oH
} Hh,q)(Wo
L%Me wU0TZ
oS, %L
//获得文件长度 lorjMS
public long getFileSize() >DPC}@Wl
{ fgq#Oi}
int nFileLength = -1; L`tr7EEr
try{ w8c71C
URL url = new URL(siteInfoBean.getSSiteURL()); %r?Y!=0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jq%Qc9y
httpConnection.setRequestProperty("User-Agent","NetFox"); #T&''a
/0@'8f\I
0]fzjiaGt
int responseCode=httpConnection.getResponseCode(); KP%A0
if(responseCode>=400) ~CQsv`
{ QT&2&#Z
processErrorCode(responseCode); +q6/'ErN]m
return -2; //-2 represent access is error ]haZT\
} %?^IS&]Z
}[\l$sS
}e s
String sHeader; o^}K]ML!t
0p)#!$
$@s&qi_&R
for(int i=1;;i++) 2ntL7F<ow
{ +7.\>Ucq`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4v_<<l
//Utility.log(in.readLine()); FxW~Co
sHeader=httpConnection.getHeaderFieldKey(i); 7'LKyy !"3
if(sHeader!=null) TY"8.vd
{ K)QMxn
if(sHeader.equals("Content-Length")) ")}^\Om
{ Uf4A9$R.G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iz.J._&
break; *2P%731n5
} I<Wp,E9G#
} &s-iie$"@x
else p(=}Qqdr8
break; Cjc>0)f&.
} +`}QIp0
} dG2k4 O
catch(IOException e){e.printStackTrace ();} Arc6d5Q
catch(Exception e){e.printStackTrace ();} =^\yE"a
3"FvYv{
?0*,x)t
Utility.log(nFileLength); &{-r 5d23
zk#"n&u0
r~nD%H:}P
return nFileLength; `tw[{Wb
} i&=I5$
<Nwqt[.
> mk>VM
//保存下载信息（文件指针位置） (E[c-1s
private void write_nPos() :#7"SEud}
{ 6?i]oy^X]p
try{ e ?sMOBPlv
output = new DataOutputStream(new FileOutputStream(tmpFile)); nvY%{Zf$}
output.writeInt(nStartPos.length); \MI2^JN
for(int i=0;i<nStartPos.length;i++) _Wg?H:\
{ 'guXdX]Gu
// output.writeLong(nPos); Td(eNe_4T
output.writeLong(fileSplitterFetch.nStartPos); X$BN&DD
output.writeLong(fileSplitterFetch.nEndPos); fqpbsM;M]
} Pu>jECcz
output.close(); >>bsr#aJ
} +-2o b90_m
catch(IOException e){e.printStackTrace ();} :8h\x
catch(Exception e){e.printStackTrace ();} B8.a#@R
} &YpViC4K.
CiF(
( f]@lNmx
//读取保存的下载信息（文件指针位置） Jui:Ms
private void read_nPos() QiKci%=SX
{ J'}G~rB<<
try{ ~?#>QN\\c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SbLm
int nCount = input.readInt(); n#$sLXVy
nStartPos = new long[nCount]; +{#65z
nEndPos = new long[nCount]; OEiu,Y|@l
for(int i=0;i<nStartPos.length;i++) Q3"{v0
{ zbY2gq@?
nStartPos = input.readLong(); 7XzhKA6
nEndPos = input.readLong(); 2i0 .x
} 3']a1\sy^
input.close(); aW=c.Q.
} @I"&k!e<2
catch(IOException e){e.printStackTrace ();} 0{Uc/
catch(Exception e){e.printStackTrace ();} R5Pk>-KF
} m#K)%0
Z=ZTSl
pmwVVUEQ
private void processErrorCode(int nErrorCode) w :nYsuF
{ 5}C.^J`
System.err.println("Error Code : " + nErrorCode); ^Y%'"QwJS
} :Oiz|b(
ml,FBBGq|-
.q90+9Ek=
//停止文件下载 ]y0bgKTK
public void siteStop() #)r^ZA&E
{ QHU|aC{r
bStop = true; |VX )S!
for(int i=0;i<nStartPos.length;i++) &u+l`F^Z
fileSplitterFetch.splitterStop(); VdL*"i
<?Ln`,Duk
pl}nbY
} C]EkVcKFA
} o|kiwr}Y
//负责部分文件的抓取 {'8td^JEE
**FileSplitterFetch.java -.@dA'j[
*/ /PZx['g
package NetFox; / f5q9sp8
Iip%er%b
|lCS^bA3
import java.io.*; 5bB\i79$
import java.net.*; ej,)<*
&2,3R}B/
HVdy!J
public class FileSplitterFetch extends Thread { CP'b,}Dd?I
'kOkwGf!
~U r
String sURL; //File URL X;bHlA-g
long nStartPos; //File Snippet Start Position HKL/D
long nEndPos; //File Snippet End Position efr9
int nThreadID; //Thread's ID Rtu"#XcBw+
boolean bDownOver = false; //Downing is over /S{U|GBB%r
boolean bStop = false; //Stop identical 6& (bL<8b
FileAccessI fileAccessI = null; //File Access interface dAWB.#
l|81_BC"
T095]*Hm
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^GpLl
{ @cr/&
this.sURL = sURL; O llS
this.nStartPos = nStart; S,Z~-j
this.nEndPos = nEnd; |*/-~5"
nThreadID = id; C547})
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q4ttmL8
} R-Ys<;
)IVk4|
%9 3R/bx
public void run() "T$LJ1E
{ b>-h4{B[
while(nStartPos < nEndPos && !bStop) Cag^$nj
{ w}]BJ<C
0QP=$X
Bs`mzA54
try{ ?edf$-"z/
URL url = new URL(sURL); {'Y()p3kl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;`O9YbP#
httpConnection.setRequestProperty("User-Agent","NetFox"); [uwn\-
String sProperty = "bytes="+nStartPos+"-"; 5X>K#N
httpConnection.setRequestProperty("RANGE",sProperty); %[, R Q">v
Utility.log(sProperty); h`dHk]O
^g|j4N
;hPVe_/
InputStream input = httpConnection.getInputStream(); ppo.#p0w
//logResponseHead(httpConnection); %+htA0aX
-{}(U
]=o1to-
byte[] b = new byte[1024]; *>/w,E]
int nRead; Lv?jg?$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hu9nJ
{ <0VC`+p<)
nStartPos += fileAccessI.write(b,0,nRead); xw}rFY$
//if(nThreadID == 1) ch2m Ei(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +DG-MM%\
} w\mTug
mGDy3R90
E-%$1=;
Utility.log("Thread " + nThreadID + " is over!"); R$!]z(
bDownOver = true; [+d~He
//nPos = fileAccessI.write (b,0,nRead); <BIQc,)2}
} ;m7~!m)
catch(Exception e){e.printStackTrace ();} ?0'e_s
} rd>>=~vx=/
} \2!.
k`#E#1niN
|$;4/cKfy
//打印回应的头信息 _&(L{cFx6
public void logResponseHead(HttpURLConnection con) T6b~uE
{ F Uz1P
for(int i=1;;i++) nuDu
{ d~MY z6"
String header=con.getHeaderFieldKey(i); |"PS e~ u
if(header!=null) GSs?!BIC
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V?Q45t Ae
Utility.log(header+" : "+con.getHeaderField(header)); 4X",:B}
else ])G|U A.
break; (t){o>l
} # >I_
} :@@`N_2?
=jKu=!QPq
T+x /J]A
public void splitterStop() W\($LD"X
{ Yecdw'BW?
bStop = true; BL~#-Mm<|l
} C=CZtjUt
#D#kw*c
w:9`R<L
} 5VpqDL~d
=`*@OJHH
>0[:uu,'>
/* ,cxe"U
**FileAccess.java }9^'etD
*//文件访问(定位，写) M)ao}m>
package NetFox; r;)31Tg
import java.io.*; A9g/At_
33KCO
skXzck
public class FileAccessI implements Serializable{ }z#M!~
@-L\c>rqT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q sUBvq
RandomAccessFile oSavedFile; FA>.1EI
long nPos; m,"-/)
}D+ b`,
w >%^pO~}`
public FileAccessI() throws IOException BW6Ox=sr<
{ ?(U;T!n
this("",0); l]~9BPsR
} n!AW9]
+)bn}L>Rl
3.Yg3&"Z
public FileAccessI(String sName,long nPos) throws IOException d2NFdBoI
{ .#Nf0
oSavedFile = new RandomAccessFile(sName,"rw"); `mW~{)x
this.nPos = nPos; @U3z@v]s(h
oSavedFile.seek(nPos); E24SD'|)
} IA&V?{OE@I
t9MCT$U
l.]wBH#RS
public synchronized int write(byte[] b,int nStart,int nLen) T{^P
{ r73W.&
int n = -1; r7].48D
try{ 5!S#}=f=
oSavedFile.write(b,nStart,nLen); gvc/Z <Y
n = nLen; +}1zw<
} mI{Fs|9h
catch(IOException e) JWaWOk(t=?
{ l53Q"ajG
e.printStackTrace (); Ywv\9KL
} +."|Y3a
?9O#b1f N
%WKBd\O
return n; 63%V_B|
} 0>Td4qr+u
N P+vi@Ud
{$Uj&/IC
} F-b]>3r
'K02T:\iZ
l`l6Y>c*]
/* ^|zag
**SiteInfoBean.java XkkzY5rxOc
*/ !;mn]wR>a
package NetFox; TmftEw>u
z;P#
F!g1.49""
public class SiteInfoBean { rNJU & .]
v0!|TI3s
!hM`Oe`S
private String sSiteURL; //Site's URL ;-JFb$m
private String sFilePath; //Saved File's Path lwgwdB
private String sFileName; //Saved File's Name E:M,nSc)53
private int nSplitter; //Count of Splited Downloading File 4eB oR%2o
6it [i@*"
YmFg#eS
public SiteInfoBean() t:V._@
{//nSplitter的缺省值为5 0G-obHe0
//default value of nSplitter is 5 iZiT/#,H2
this("","","",5); EI*~VFx
} P qC#[0Qy
+jZa A/
i/n ee_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *k_<|{>j(
{ WEX7=^k9
sSiteURL= sURL; 8f[ztT0`g
sFilePath = sPath; [ dVBsi
sFileName = sName; fCN+9!ljG`
this.nSplitter = nSpiltter; LxGD=b
kvbW^pl
T[xIn+w
} @VW1^{.do^
AZ4?N.X?
7gV9m9#
public String getSSiteURL() -C(Yl=
{ $:oC\K6
return sSiteURL; MZX)znO
} 0;T7fKj
I}o} #OJ
L~)8Q(f
public void setSSiteURL(String value) `Mt|+iT$p
{ B+~ /-3
sSiteURL = value; c1i:m'b_5
} #$k1w@
Yb`b/BMR
(0#$%US\
public String getSFilePath() *yw!Y{e!9
{ U^GVz%\
return sFilePath; ,g}$u'A+d
} ]S]W|m7=.Z
8rS;}Bt
e(a,nZF.
public void setSFilePath(String value) hKN ;tq,
{ C P&u
sFilePath = value; =y@0il+V
} GRYw_}Aa
,{S $&g*
"ldd&><
public String getSFileName() 4v_Hh<%
{ ,aUbB8
return sFileName; 0fBwy/:
} /3rNX}tOMH
2jC:uk
ogQfzk
public void setSFileName(String value) RD)Vb$.B:
{ u0arJU_.)
sFileName = value; ]i6*$qgma
} \+sa[jK
b\H&E{Gn|x
(M1YOK)I
public int getNSplitter() M_UmnqN1C
{ bri8o"
return nSplitter; kiN,N]-V
} W/,:-R&'>
r9N?z2X
Cj4Y, N
public void setNSplitter(int nCount) k Qr
{ c CDT27@
nSplitter = nCount; |5dNJF8;Q
} 6Y\TVRR
} ZAy/u@qt
WxO+cB+?
X>uLGr>
/* |O>e=HC#q8
**Utility.java d7r!<u&/
*/ gt.F[q3
package NetFox; ;>6~}lMgJ
wE=I3E%
f&^"[S"\f
public class Utility { L-}Uj^yF
pGR3
3b0|7@_E
public Utility() \6/Gy!0h-
{ fgj$ u
/0gr?I1wr7
2bw), W
} Dzu//_u
BH~zeJ*Pr
//线程睡眠 r0[<[jEh
public static void sleep(int nSecond) 8N"WKBj|_d
{ h x5M)8#+
try{ CYE[$*g6y
Thread.sleep(nSecond); x"C7NW[$
} %>9L}OAm
catch(Exception e) [QQM/?
{ _oG%bNM
e.printStackTrace (); hg0{x/Dgny
} x`C"Z7t
} _6h.<BR
Hik=(pTu>
//日志 ]R}(CaT1
public static void log(String sMsg) yl@Nyu
{ S _U |w9q
System.err.println(sMsg); 8LPWT!S
} %B#T"=Cx
zY*~2|q,s
Cc{{9Ud
public static void log(int sMsg) HbB8A#u
{ ]u-bJ
System.err.println(sMsg); AD`5:G
} H? z~V-8
} 2BF455e
O>nMeU
{j`8XWLZZN
/* L;M@]
**TestMethod.java s1::\&`za
*/ :tnW ivrwR
package NetFox; k\SqDmv
UNiK6h_%
S!$S'{f<
public class TestMethod { y5aPs z
pT~3< ,
H}G 9gi
public TestMethod() :8/ 6dx@Y(
{ ///xx/weblogic60b2_win.exe (=WYi~2v
try{ F|m &n&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); YCb|eS^u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Btzes.
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8pr toCB
fileFetch.start(); $n!5JS@40
} z>,tP
catch(Exception e){e.printStackTrace ();} U" 3L
JtMl/h
Hq<4G:#
} iQ2}*:Jc$
Vfk"}k/do
J[Mj8ee#
public static void main(String[] args) Ev3'EA~`
{ C:^ :^y
new TestMethod(); V;CRs\aYf
} "mE/t (
} i!UT =
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