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)); tlD^"eq4:
} *q=\e9
for(int i=0;i<nEndPos.length-1;i++) s?m_zJh
{ xg, 9~f[
nEndPos = nStartPos[i+1]; xLFMC?I
} ~E8/m_> rU
nEndPos[nEndPos.length-1] = nFileLength; W&cs&>F#
} zj2y=A|Y
} r`sKe &
zfI{cMn'J
Zy9IRZe4U
//启动子线程 9]ZfSn)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nM&a2Z,T
for(int i=0;i<nStartPos.length;i++) k)D5>T
{ > O?<?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eQ)*jeD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <5j%!6zo
nStartPos,nEndPos,i); "2-D[rYZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LqI&1$#
fileSplitterFetch.start(); _i7yyt;h
} EX!`Zejf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `5oXf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @>$qb|j
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jPz1W4pk
nEndPos = " + nFileLength); GY@:[u.&
// fileSplitterFetch[nPos.length-1].start(); seAPVzWUU
<w*WL_P
0S>L0qp
//等待子线程结束 ](n)bF+ym
//int count = 0; l?_Fy_fBt
//是否结束while循环 XABP}|aWK
boolean breakWhile = false; JQej$=*
6hR `sE
F?FfRzZ[
while(!bStop) #b)`as?!1
{ [+W<;iep
write_nPos(); Yc6.v8a
Utility.sleep(500); ~;]zEq-hG
breakWhile = true; vN_ 8qzWk
kzK9.
Hq gg*4#
for(int i=0;i<nStartPos.length;i++) fyT|xI`iD
{ nvwf!iU6
if(!fileSplitterFetch.bDownOver) b?,%M^9\`
{ :EYUBtTj
breakWhile = false; `s+kYWg'Z
break; :Sd`4"AA
} H0])>1sWB
} 8_Uhh5[
if(breakWhile) (xTGt",_Jo
break; $'eY-U8q
k$f2i,7'
;-"q;&1e
//count++; 9I<~t@q5e@
//if(count>4) +G"YQq'b
// siteStop(); GNrRc3dr$
} bd}[X'4d
H n]( )/
0J466H_d{
System.err.println("文件下载结束！"); b3 =Z~iLv
} YIgHLM(
catch(Exception e){e.printStackTrace ();} (G{S*+
} :O&jm.2m
dXM8iP
Y}2Sr-@u
//获得文件长度 `[}X_d 1A
public long getFileSize() zAklS 7L
{ ?D)$OCS
int nFileLength = -1; *pnaj\
try{ %-K5sIz
URL url = new URL(siteInfoBean.getSSiteURL()); -$g~,dIwj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @b.,pwZF
httpConnection.setRequestProperty("User-Agent","NetFox"); KDGrX[L:6
'PFjZGaKR
FAM:; F30
int responseCode=httpConnection.getResponseCode(); #QcRN?s
if(responseCode>=400) @+p(%
{ /)K;XtcN
processErrorCode(responseCode); ]63! Wc
return -2; //-2 represent access is error u=]*,,5<
} !=*8*?@
ewdTsgt'
vV9vB3K5?
String sHeader; 0#uB[N
c[ 0`8s!
Piwox1T;
for(int i=1;;i++) ,!%E\`
{ emrA!<w!W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "sDs[Lcq
//Utility.log(in.readLine()); lP]Y^Gz
sHeader=httpConnection.getHeaderFieldKey(i); OQ wO7Z
if(sHeader!=null) z9OpxW@Ou
{ ,tyPZR_
if(sHeader.equals("Content-Length")) j} ^3v #
{ 5}]+|d;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $Q'z9ghEg
break; X9FO"(J
} 4L{]!dox
} kMnG1K
else U{pg y#/
break; ]a~sJz!
} N#e9w3Rli
} =VZ_';b h
catch(IOException e){e.printStackTrace ();} ?(K=du
catch(Exception e){e.printStackTrace ();} \>lA2^Ef
2?Jw0Wq5D
Xfqin4/jC
Utility.log(nFileLength); m}RZ)c
m9:ah<
1%N*GJlwJ
return nFileLength; ?fq!BV
} g%[:wjV;
v;;3 K*c>
8uH8)
//保存下载信息（文件指针位置） vo*oCfm
private void write_nPos() `Z5dRLrd
{ VR&dy|5BO
try{ Z^as ?k(iM
output = new DataOutputStream(new FileOutputStream(tmpFile)); S!z3$@o
output.writeInt(nStartPos.length); |#Lz0<c;
for(int i=0;i<nStartPos.length;i++) y1PyH
{ ,~ZD"'*n6g
// output.writeLong(nPos); $*%,
output.writeLong(fileSplitterFetch.nStartPos); ?H@<8Ra=3
output.writeLong(fileSplitterFetch.nEndPos); gSw<C+
} $rr@3H+
output.close(); "uIaKb
} \$Wpt#V
catch(IOException e){e.printStackTrace ();} @,k5T51m
catch(Exception e){e.printStackTrace ();} (Y7zaAG]
} 5BXku=M
$S?gQN.e
"H`Be
//读取保存的下载信息（文件指针位置） ][?J8F
private void read_nPos() >JS^yVk
{ ^4"AWps
try{ sr&W+4T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0D@$
int nCount = input.readInt(); !\BZ_guz
nStartPos = new long[nCount]; 1Pw1TO"Z
nEndPos = new long[nCount]; ^w~B]*A:"
for(int i=0;i<nStartPos.length;i++) g:JSy
{ $'Mf$h
nStartPos = input.readLong(); Q35\wQ#
nEndPos = input.readLong(); bK~Toz<k
} Sm4BZF~!B
input.close(); At=d//5FFP
} 8/dMvAB1So
catch(IOException e){e.printStackTrace ();} LPJ7V`!k
catch(Exception e){e.printStackTrace ();} sV%DX5@
} =NC??e{
Po@;PR=
|w{Qwf!2
private void processErrorCode(int nErrorCode) U[?_|=~7
{ Zc1x"j
System.err.println("Error Code : " + nErrorCode); 5{V"!M+<
} 1r$-Uh
TQ4L~8
}5oI` 9VT
//停止文件下载 6 V0Ayxg7
public void siteStop() #Iz)Mu
{ #c@&mus
bStop = true; 13#ff
for(int i=0;i<nStartPos.length;i++) nD*iSb*
fileSplitterFetch.splitterStop(); qovsM M
<.4(#Ebd
N?vb^?
} Vl5>o$G|<.
} L7 }nmP>aR
//负责部分文件的抓取 ;HXk'xN
**FileSplitterFetch.java $-1ajSVJ
*/ 0x-g0]
package NetFox; 2n@`Og_0
PtW2S 1?j
t7F0[E'=5\
import java.io.*; 2'S&%UyP
import java.net.*; d%'#-w'
`Fr ,,Q81\
2\1+M)
public class FileSplitterFetch extends Thread { {HEWU<5
AtCT
\]Ah=`
String sURL; //File URL o( zez
long nStartPos; //File Snippet Start Position (cLKhn@
long nEndPos; //File Snippet End Position jC>ZMy8U)4
int nThreadID; //Thread's ID N { oVz],
boolean bDownOver = false; //Downing is over Nz`8)Le
boolean bStop = false; //Stop identical T"Y#u
FileAccessI fileAccessI = null; //File Access interface <9fXf*
H;nzo3x
Zio!j%G
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y`ip.Nx
{ *%;A85V/
this.sURL = sURL; 9S]pC?N]E
this.nStartPos = nStart; ~&)\8@2
this.nEndPos = nEnd; U%:%. Bys
nThreadID = id; Ljz)%y[s
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?l6yLn5si^
} a^J(TW/
/8qR7Z^HZ
Hl8-q!
public void run() mnM]@8^G
{ sX~E ~$_g
while(nStartPos < nEndPos && !bStop) |(%<FY$
{ n>.@@
g3kbsi7_:
Hu<]*(lK%
try{ lot`6]
URL url = new URL(sURL); @QmN= X5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wd*B3
httpConnection.setRequestProperty("User-Agent","NetFox"); H I|a88
String sProperty = "bytes="+nStartPos+"-"; ]j7`3%4uK
httpConnection.setRequestProperty("RANGE",sProperty); p+=zl`\=|
Utility.log(sProperty); AJi+JO-
t!rrYBSCr
3'.3RKV
InputStream input = httpConnection.getInputStream(); }~@/r5Zl
//logResponseHead(httpConnection); r[Pp[g-J
2K>1,[C'Z
p4z4[=-:
byte[] b = new byte[1024]; ),N,!15j,
int nRead; UiV#w#&P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) eWv:wNouk
{ QO;Dyef7b
nStartPos += fileAccessI.write(b,0,nRead); 'hr_g* i
//if(nThreadID == 1) `e'wWV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jt]RU+TB
} %l&oRBC
kBk>1jn"
~F-knEvL
Utility.log("Thread " + nThreadID + " is over!"); Q(w;
bDownOver = true; ^?Xs!kJP
//nPos = fileAccessI.write (b,0,nRead); }'wZ)N@
} "|(.W3f1
catch(Exception e){e.printStackTrace ();} %|H]T]s
} eowwN>-2C
} Y(6evo&IR
`G!HGzVx;j
Nxt:U{`T'
//打印回应的头信息 &'^.>TJ\
public void logResponseHead(HttpURLConnection con) *ilh/Hd>
{ H}GGUE&c*
for(int i=1;;i++) \l(J6Tu
{ 1#3|PA#>
String header=con.getHeaderFieldKey(i); (mP{A(kwJ
if(header!=null) FLG"c690
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )lLeL#]FLO
Utility.log(header+" : "+con.getHeaderField(header)); _(g0$vRP~
else 15J"iN2"W
break; %]7 6u7b/
} b|.Cqsb
} t!3s@
lv/im/]v
X>`03?L
public void splitterStop() qZF&^pCF}
{ mmJnE
bStop = true; py\:u5QS
} AJB NM
stK}K-=`
f@YdL6&d-
} U)f('zD
nxhlTf>3
P]n0L4c
/* m2^vH+wD
**FileAccess.java M>5OC)E
*//文件访问(定位，写) "|I.j)
package NetFox; C~4SPCU
import java.io.*; J|{50?S{^
v|~=rvXFC
swZi O_85
public class FileAccessI implements Serializable{ uz+WVmb
A^FkU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #pPOQv:~
RandomAccessFile oSavedFile; .n8O 3V
long nPos; 6e#wR/
M/#U2!iFk
t77'fm
public FileAccessI() throws IOException v459},!P
{ ]fE3s{y &-
this("",0); F;kvH
} V#J"c8n
oLS7`+b$
tS<h8g_
public FileAccessI(String sName,long nPos) throws IOException fY_%33_I$
{ e+@xsn3
oSavedFile = new RandomAccessFile(sName,"rw"); b_vTGl1_6
this.nPos = nPos; {eR9 ;2!
oSavedFile.seek(nPos); S}cF0B1E*
} v[&'k\
fHfY}BQS
nxQ}&n
public synchronized int write(byte[] b,int nStart,int nLen) XLb0 9;
{ Hku=pr3Gn
int n = -1; fsvYU0L
try{ k1fRj_@WPT
oSavedFile.write(b,nStart,nLen); 31}W6l88c
n = nLen; 0S.?E.-&0
} rk,p!}FqL
catch(IOException e) -H\,2FO
{ uD(t`W"
e.printStackTrace (); J]fS({(\I
} t5)J;0/
"'A"U
V;93).-$
return n; ;|TT(P:d
} qks|d_
f1Zt?=
TpP8=8_Lh
} |Q!4GeQL[
-t4 [oB
Q4wc-s4RN
/* 5AOfp2O
**SiteInfoBean.java Jqru AW<
*/ 16$y`~c-z
package NetFox; R2LK.bTVn
<zfKC
CgnXr/!L
public class SiteInfoBean { 6[?}6gQ
1q]c7"
ut5yf$%
private String sSiteURL; //Site's URL wFL3&*
private String sFilePath; //Saved File's Path ez*jjm
private String sFileName; //Saved File's Name %S#WPD'Y
private int nSplitter; //Count of Splited Downloading File >5Lexj
NHiq^ojk
&qRJceT(
public SiteInfoBean() Q6^x8
{//nSplitter的缺省值为5 0YS?=oi
//default value of nSplitter is 5 EXpSh}
this("","","",5); 0H:dv:#WAI
} @GGccF
[rdsv
\9/1L?@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )|]Z>>%t
{ hz)9"B\S
sSiteURL= sURL; 4P kfUMX
sFilePath = sPath; {L0;{
sFileName = sName; nGrVw&
this.nSplitter = nSpiltter; yP\Up
0"4@;e_)>
8D~x\!(p\
} BUC,M:J+H
X\sm[_I
T[.[ g/`
public String getSSiteURL() (@&I_>2Q
{ x / XkD]Hq
return sSiteURL; nNn56&N]
} e.;M.8N#SQ
I/p]DT
L11L23:
public void setSSiteURL(String value) 'sU)|W(3U
{ _CdROo6I
sSiteURL = value; LprM;Q_
} =!<G!^
>oqZ !V5[
9]$`)wZ
public String getSFilePath() ^ KH>1!
{ V5MO}
return sFilePath; [7\>"v6
} f a5]a
,w`~K:b.
a%K}j\M
public void setSFilePath(String value) {Y_Nj`#BT
{ jA`a/vWu
sFilePath = value; ;KcFy@ 6q5
} ty- r&
SrZ50Se
- L~Uu^o
public String getSFileName() PqEAqP
{ a[C&e,)}
return sFileName; =`p&h}h-L
} $G[KT):N
Y4To@TrN#\
u!1/B4!'O
public void setSFileName(String value) GqUSVQ
{ _01Px a2.
sFileName = value; YIOR$
} 3k{ @.V?]
J}@GKNm
9X]f[^
public int getNSplitter() Efr&12YSS
{ )w"0w(
return nSplitter; ;.s:X
} /DU*M,
8"M<{72U]
grbTcLSF
public void setNSplitter(int nCount) V^En8
{ 7a<_BJXx
nSplitter = nCount; ]^@0+!
} \_ -DyD#3
} @ER1zKK?
~zyQ('
cht
/* xIgql}.
**Utility.java }m_t$aaUc1
*/ UC|JAZL
package NetFox; AZwa4n}"
%fpsc_
\!wh[qEQ\
public class Utility { F^rl$#pCS
}n95< {
RVP18ub.S
public Utility() $4Y&j}R
{ t w!.%_1^
}17bV, t
76cEKHa<
} ,?y7,nb
*<k&#D"m
//线程睡眠 k1iLnza%
public static void sleep(int nSecond) C BlXC7_Mi
{ XU-*[\K
try{ ~:Ixmqi}R
Thread.sleep(nSecond); q?iCc c
} hbnS~sva
catch(Exception e) mJ$Htyr
{ $e1:Q#den2
e.printStackTrace (); <[9?Rj@
} 3{pk5_c
} SG`)PW?
6Ahr_{
//日志 yFO)<GLk
public static void log(String sMsg) d h?dO`
{ f".q9{+p,
System.err.println(sMsg); R&!]Rl9hf
} gvo?([j-m
i;]CL[#2e`
D1ZC&B_}-
public static void log(int sMsg) f9F2U )
{ :<UtHf<=k
System.err.println(sMsg); 5Hy3\_ +
} <Wf0QO,
} eP?~-#
kp; &cQu!
mt^`1ekoY
/* |hD~6a
**TestMethod.java 6Pijvx^0
*/ m9Il\PoTq
package NetFox; 1t#XQ?8
"ZqEP R)
`:gYXeR
public class TestMethod { QES^^PQe:
UAKu_RO6S
^(g_.>
public TestMethod() LUG9 #.
{ ///xx/weblogic60b2_win.exe dm 2EH
try{ KcnjF^k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `~h0?g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6Wb!J>93
SiteFileFetch fileFetch = new SiteFileFetch(bean); )r pD2H
fileFetch.start(); F;W'
} :ovt?q8">
catch(Exception e){e.printStackTrace ();} RY9.n
Onyh1
?#i|>MRR>
} F#KF6)P
aC}p^Nkr"k
X7b!;%3@
public static void main(String[] args) o Fi) d[`
{ jVs(x
new TestMethod(); .=CH!{j
} V4Qz*z%
} k1m'Ka-
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