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)); tON>wmN
} sFFQ]ST2p
for(int i=0;i<nEndPos.length-1;i++) |EE1S{!24m
{ 6^Wep- $
nEndPos = nStartPos[i+1]; &|>~7(
} GF ux?8A:%
nEndPos[nEndPos.length-1] = nFileLength; |HK:\)L%
} ZUQ _u
} >Wr%usNxc
d<a|dwAeh
O{LCHtN
//启动子线程 '}_r/l]K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z0Z6aZeb
for(int i=0;i<nStartPos.length;i++) Xi&J%N'
{ W*C~Xba<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I$7eiW @
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +& r!%j7
nStartPos,nEndPos,i); OjUPvR2 0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WBE>0L
fileSplitterFetch.start(); C{}_Rb'x
} @V*dF|# /
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q\6(_U#Tl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D`LBv,n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B3#G
nEndPos = " + nFileLength); !K>iSF<
// fileSplitterFetch[nPos.length-1].start(); KMRPleF
=5+*TL`
sasurR|;
//等待子线程结束 6z9 '|;,4
//int count = 0; TQ4@|S:OF
//是否结束while循环 Urr%SIakvM
boolean breakWhile = false; PE%$g\#?
1)(>'pY
-* ,CMw
while(!bStop) $O%{l.-O
{ @[n#-!i
write_nPos(); rpT.n-H>%A
Utility.sleep(500); L80(9Y^xn
breakWhile = true; ~Bzzu %S
bKo %Ak,
L!fTYX#K]
for(int i=0;i<nStartPos.length;i++) ote,`h
{ Wgwd?@uK
if(!fileSplitterFetch.bDownOver) j#](Q!
{ i5 rkP`)j
breakWhile = false; gfQ?k
break; W$c@C02<
} n<ZPWlJ
} ;m(iKwDt
if(breakWhile) ^dQ{vL@9b9
break; 8+F5n!
Kw -SOFE
ot^pxun
//count++; @5%&wC
//if(count>4) "7B}hZ^)W
// siteStop(); ?5C'9 V
} ]\78(_o.zz
rJ!cma
Z3`EXs
System.err.println("文件下载结束！"); >@YefNX6
} tEhg',2t(
catch(Exception e){e.printStackTrace ();} ,EB}IG]
} z5>I9R^q;
H71sxek3
K;?D^n.
//获得文件长度 P-@MLIC{
public long getFileSize() 7zM:z,
{ cl4E6\?z
int nFileLength = -1; ^Bx[%
try{ fj_23{,/"g
URL url = new URL(siteInfoBean.getSSiteURL()); ";K w?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >fPo_@O
httpConnection.setRequestProperty("User-Agent","NetFox"); QZ a.c
/DYyl/
X]0>0=^
int responseCode=httpConnection.getResponseCode(); <L&EH@T
if(responseCode>=400) *DL7p8
{ OK[J h
processErrorCode(responseCode); {K,In)4
return -2; //-2 represent access is error 4-(kk0]`z
} Y=Vbs x
%Y^J''
oUv26t~
String sHeader; a{5SOe;;
#z `W ,^C
J+6zV m
for(int i=1;;i++) @A/k"Ax{r
{ 1vj/6L
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F!omkN
//Utility.log(in.readLine()); 4U}qrN~=
sHeader=httpConnection.getHeaderFieldKey(i); "/W[gP[y%
if(sHeader!=null) 3N7H7(IR
{ uDF;_bli)H
if(sHeader.equals("Content-Length")) Fhoyji4
{ %Sr+D{B
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9njwAKF?
break; )BP*|URc
} tdy2ZPVtTV
} ;XKe$fsa~?
else a)qan
break; 6 63o
} T{YZ`[
} MY&Jdmga
catch(IOException e){e.printStackTrace ();} Swi#^i
catch(Exception e){e.printStackTrace ();} ($[wCHU`!
[ERZ".?
zZ5:)YiW-
Utility.log(nFileLength); ep0,4!#FAO
!IxO''4
S{@}ECla
return nFileLength; zkQ[<
} +X}i%F'
"t@p9>
*H>rvE.K?
//保存下载信息（文件指针位置） rqdwQ
private void write_nPos() \@LTXH.
{ ^J!q>KJs
try{ bx@l6bpQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); {T){!UVp!
output.writeInt(nStartPos.length); *b~6 BM$
for(int i=0;i<nStartPos.length;i++) p?@ %/!S
{ @mp`C}x"0&
// output.writeLong(nPos); je4l3Hl
output.writeLong(fileSplitterFetch.nStartPos); bDI%}k9#
output.writeLong(fileSplitterFetch.nEndPos); 6@S6E(^
} :2 ;Jo^6Se
output.close(); KyvZ?R
} G0cG%sIl
catch(IOException e){e.printStackTrace ();} TkbaoD
catch(Exception e){e.printStackTrace ();} I[\~pi,
} UM}u(;oo%)
}pc9uvmIJ
O] _4pP
//读取保存的下载信息（文件指针位置） 7nZPh3%
private void read_nPos() e#eVc'=cDR
{ bF)G+IH
try{ hsZ/Vnn`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~%TWF+
int nCount = input.readInt(); nla6QlFYn*
nStartPos = new long[nCount]; \bA Yic
nEndPos = new long[nCount]; Z:;}
for(int i=0;i<nStartPos.length;i++) 9>""xt
{ R%E7 |NAG
nStartPos = input.readLong(); bS.w<V Ew
nEndPos = input.readLong(); DSGcxM+
} )G? qX.D
input.close(); d_RgKdR )k
} >tD=t8
catch(IOException e){e.printStackTrace ();} JTlk[c
catch(Exception e){e.printStackTrace ();} IgT`on3Y
} &4#Zi.]
bp1AN9~
.8hI ad
private void processErrorCode(int nErrorCode) 2hE(h
{ Ia&R/I
System.err.println("Error Code : " + nErrorCode); Uv^\[
} 2|1fb-AR
&hCbXs=
'6KvB
//停止文件下载 <N<Q9}`V
public void siteStop() EeIDlm0o
{ I7f ^2
bStop = true; f)I5=Ijy(
for(int i=0;i<nStartPos.length;i++) _GOSqu!3Y
fileSplitterFetch.splitterStop(); J 3!~e+wn
H'+7z-%G
{4"V)9o-1>
} :5d>^6eoB?
} S{YzHK
//负责部分文件的抓取 u8e_Lqx?
**FileSplitterFetch.java OWd'z1Yl
*/ GkIE;7#2kX
package NetFox; *bkb-nKw
!>UlvT-
{Gxe%gu6K
import java.io.*; /--p#Gh'
import java.net.*; t6+m` Kq
)?n'ZhsX
\-<BUG]=
public class FileSplitterFetch extends Thread { c:[k+_Zr
V+d_1] l
"fFSZ@,r
String sURL; //File URL {(73*-~$
long nStartPos; //File Snippet Start Position ]B8 A
long nEndPos; //File Snippet End Position 0.aXg"
int nThreadID; //Thread's ID ;*K4{wvG
boolean bDownOver = false; //Downing is over rIb+c=|F
boolean bStop = false; //Stop identical Vej$|nF
FileAccessI fileAccessI = null; //File Access interface <LX\s*M)
O5\r%&$xd
gN&i&%*!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pO]gf$
{ zF&VzNR2
this.sURL = sURL; %36x'Dn?
this.nStartPos = nStart; }xZi Ct
this.nEndPos = nEnd; :yay:3qv
nThreadID = id; h8rW"8Th
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Fu7:4+
} !,4ag1
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:1v,QEb\
public void run() |rmelQ-
{ 4=PjS<Lu8
while(nStartPos < nEndPos && !bStop) CB@7XUR
{ ^E&PZA\,;
8$00\><r
b*|~F
try{ =Q#I@SVp2$
URL url = new URL(sURL); ^:nc'C gP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SnCwoxK
httpConnection.setRequestProperty("User-Agent","NetFox"); :=QX^*
String sProperty = "bytes="+nStartPos+"-"; qHtQ4_Zn;
httpConnection.setRequestProperty("RANGE",sProperty); R!nf^*~
Utility.log(sProperty); ?u|??z%
7WJ\nK
VK}4<u
InputStream input = httpConnection.getInputStream(); {@Wv@H+4
//logResponseHead(httpConnection); rTD+7 )E
?vXgHDs^T
gLiJ&H
byte[] b = new byte[1024]; Dc9uq5l
int nRead; k.@![w\ea
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cx}Yu8
{ 3G})$y3m
nStartPos += fileAccessI.write(b,0,nRead); Z~'t'.=z
//if(nThreadID == 1) ]TV_p[L0B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'C+cQLig@
} z2=bbm:
V>6klA}o
F^ q{[Z
Utility.log("Thread " + nThreadID + " is over!"); 4vhf!!1
bDownOver = true; MlO OB
//nPos = fileAccessI.write (b,0,nRead); )XI[hVUA
} X1o",,N^M
catch(Exception e){e.printStackTrace ();} 7*:zN
} ]8$8QQc<<5
} ;\MWxh,K
XqH@3Ehk
^W |YE72Y
//打印回应的头信息 'Waazk[@O
public void logResponseHead(HttpURLConnection con) K;K0D@>]HR
{ X+vKY
for(int i=1;;i++) ;?h[WIy
{ LG}{ibB
String header=con.getHeaderFieldKey(i); kR]P/4r
if(header!=null) q8 v iC|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z4u&#.bU
Utility.log(header+" : "+con.getHeaderField(header)); <T2O^
else x6ghO-s
break; j#HXuV6
} }1a}pm2p
} ["Zvwes#7
.#EU@Hc
\S}/2]* 1
public void splitterStop() zAgX{$/Fg
{ Z0gtliJ@
bStop = true; ;QI9OcE@/
} D 0Xl`0"'
p1N}2]e
IQqUFP$8g
} *>fr'jj1$
*^>" h@J
+VwQ=[y]
/* hgU;7R,?ir
**FileAccess.java ]jT}]9Q$
*//文件访问(定位，写) 6<&~R3dQ
package NetFox; KsDS!O
import java.io.*; U}92%W?
hBgE%#`s
>?g@Nt8
public class FileAccessI implements Serializable{ j^G=9r[,
>%/x~UFc5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yT^x0?U
RandomAccessFile oSavedFile; {16a P
long nPos; 'g#%>
)~2\4t4|g
\JLGw1F
public FileAccessI() throws IOException Bdo{zv&A
{ y r (g/0
this("",0); W"\~O"a
} x&B&lFmo8
6w.E Sm
vCa8`m
public FileAccessI(String sName,long nPos) throws IOException 3%v)!dTa<^
{ Vl.,e1)6
oSavedFile = new RandomAccessFile(sName,"rw"); #W\}v(Ke
this.nPos = nPos; ;i@S}LwL
oSavedFile.seek(nPos); Yf0 KG
} }[+uHR6L
=Rd`"]Mnfb
U`v2Yw3E
public synchronized int write(byte[] b,int nStart,int nLen) "@ >6<(Ki
{ +pd,gG?dW
int n = -1; X[tt'5
try{ s-p)^B
oSavedFile.write(b,nStart,nLen); HxI6_>n^I
n = nLen; J4bP(=w!
} A?R`~*Q5
catch(IOException e) 91OxUVd
{ 2z>-H595az
e.printStackTrace (); ;"dX]":
} zlMh^+rMX
.n:Q~GEL
sXVl4!=l6
return n; \Vc[/Qp7Bb
} rr#nBhh8
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"i&)+dr-
} B{Q}^Mcxy
<rC%$tr
G,C`+1$*
/* 5 -i,Tx&:
**SiteInfoBean.java ~ l}f@@u
*/ !y_FbJ8KC
package NetFox; 9xA4;)36
Hf4_zd
{Y~>&B5
public class SiteInfoBean { }`=7%b`-?
e=;A3S
CR4O#f8\
private String sSiteURL; //Site's URL Avx`
private String sFilePath; //Saved File's Path i'fw>-0
private String sFileName; //Saved File's Name Jn+-G4h$
private int nSplitter; //Count of Splited Downloading File ?Q:SVxzUd
w=KfkdAJ*/
sx?IIFF
public SiteInfoBean() - 2)k!5X=
{//nSplitter的缺省值为5 pRQ7rT',v
//default value of nSplitter is 5 <]Td7-n
this("","","",5); TV`1&ta
} 99yWUC,
3IxC@QR
t/|0"\ p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gIo\^ktW
{ aM5]cc%
sSiteURL= sURL; ?/|Xie
sFilePath = sPath; @$ 7 GrT
sFileName = sName; @=kgK[t 9
this.nSplitter = nSpiltter; ky2]%cw
?:r?K|Ku
=lAjQt
} u X,n[u
L{/% "2>
O Z ./suR)
public String getSSiteURL() jNj;#C)
{ UJO3Yn
return sSiteURL; etX@z'H
} ,Zmjw@w
)N 3^r>(e<
TcZ.5Oe6h#
public void setSSiteURL(String value) >pu4G+M
{ k4Q>J,k
sSiteURL = value; HV%/baX]
} xPZ>vCg
{aAd (~YZ
1ksFxpE
public String getSFilePath() X]y:uD{
{ b8d0]YS
return sFilePath; q,Gymh;
} <7P[)X_
97liSd
^J]&($-
public void setSFilePath(String value) `W86]ut[
{ : UeK0
sFilePath = value; *)K\&h<{
} 1L,L/sOwB&
R-%6v2;ry
$0$sM/%
public String getSFileName() NP;W=A F
{ um%_kX
return sFileName; 5L3+KkX@
} ^PEw#.WG
"Z&.m..gc
v,i|:;G
public void setSFileName(String value) 4jXo5SkEJ
{ & /8Tth86
sFileName = value; gqS9{K(f
} 0+SDFh
tWn dAM(U7
a&>NuMDI
public int getNSplitter() +q&Hj|;8r
{ SnE^\I^O
return nSplitter; ?^voA.Bv<
} d,GOP_N8I
|Gic79b
X['9;1Xr
public void setNSplitter(int nCount) 6f +aGz
{ f<8Hvumw
nSplitter = nCount; lpG%rN!
} ^/BGOBK
} k6CXuU
;VE y{%nF
m*m),mZ"
/* >Y>R1b%
**Utility.java 811>dVq3/
*/ #gbB// <
package NetFox; 2.3_FXSt
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public class Utility { gsL=_# ?
w0!$ow.l
BwT[SI<Sg
public Utility() Jk*cuf`rq
{ @` KYgjjH
,;,B7g
l@);U%\pS
} .D W>c}1
o-6d$c}{f
//线程睡眠 `<9>X9.+
public static void sleep(int nSecond) LGt>=|=bj
{ c`<2&ke
try{ 3y)\dln
Thread.sleep(nSecond); PCl5,]B}
} dJR[9T_OF
catch(Exception e) sqKx?r72
{ vIpL8B86a
e.printStackTrace (); VKttJok1
} ) lUS'I
} ^Wld6:L{I
tLu&3<%
//日志 E7$&:xqx
public static void log(String sMsg) [[|#}D:L
{ V}V->j*
System.err.println(sMsg); vK!`#W`X
} *s4|'KS2o
[Vs\r&qL
iaL@- dg
public static void log(int sMsg) ~YH?wdT
{ E`TZ:W]r,
System.err.println(sMsg); @6UtnX'd
} a/ Ac^!(
} !R8%C!=a
R&|.Lvmc/
MtJ-pa~n
/* :{a< ~n`
**TestMethod.java pyhXET '
*/ >W>rhxU
package NetFox; }r,M(Zr
h:fiUCw
[e><^R*u
public class TestMethod { 9d"*Z%!j
JX0M3|I=
ox&5}&\
public TestMethod() 3%*igpj\)
{ ///xx/weblogic60b2_win.exe z3aGK
try{ %"`p&aE:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PIH\*2\/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1h@qcom9K_
SiteFileFetch fileFetch = new SiteFileFetch(bean); @JGmOwZ
fileFetch.start(); $5pCfW8>
} ehW[LRtq
catch(Exception e){e.printStackTrace ();} qcs) p
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ob>)F^.iS
} eB~\~@
u 8o!
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public static void main(String[] args) @V:K]M 5
{ q=t!COS
new TestMethod(); O=A R`r#u
} g}%ODa !H
} ;7\Fx8"s[
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