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)); Nm.G,6<J
} yPXa
for(int i=0;i<nEndPos.length-1;i++) K}j["p<!
{ aB*'DDlx"r
nEndPos = nStartPos[i+1]; wdo(K.m
} w28&qNha
nEndPos[nEndPos.length-1] = nFileLength; mY1Gm|
} ]o<&Q52|
} M8{J
{IgLH`@
yRyUOTK
//启动子线程 d"0=.sA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^1mnw@04
for(int i=0;i<nStartPos.length;i++) CAT{)*xc
{ 5"WI^"6b:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N7 ox#=g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hC D6
nStartPos,nEndPos,i); ,%X"Caz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LuE0Hb"S8
fileSplitterFetch.start(); h%UM<TZ]"
} qe<xH#6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >.o<}!FW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W Yo>Md 8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %5yP^BL0
nEndPos = " + nFileLength); ;ZtN9l
// fileSplitterFetch[nPos.length-1].start(); fG_<HJS(~
?l>Ra0
#9e2+5s
//等待子线程结束 T jrz_o)
//int count = 0; r"&uW!~0
//是否结束while循环 b'1m 9T780
boolean breakWhile = false; %+: $uk[
8c3/n
N#<X"&-_#
while(!bStop) )zv"<>Q 6
{ O/b1^ Y
write_nPos(); ?[#4WH-G
Utility.sleep(500); Memb`3
breakWhile = true; \f-@L;8#
"~:P-]`G
uGU-MC*
for(int i=0;i<nStartPos.length;i++) >v'@p
{ Z/e^G f#i
if(!fileSplitterFetch.bDownOver) %$6?em_
{ u/.# zn@9h
breakWhile = false; EL^j}P
break; Ov~vK\
} 9 K~X+N\
} &ev#C%Nu
if(breakWhile) CsX@u#
break; ^OrO&w|
l[Ko>
u$rSM0CJ
//count++; %{B4M#~
//if(count>4) >uP1k.z'I
// siteStop(); 7TB&Q*Zf
} cMoBYk
W_bA.zT{
=J0r,dR
System.err.println("文件下载结束！"); 2= )V"lR\
} ?Ll1B3f
catch(Exception e){e.printStackTrace ();} 95.s,'0
} eHc.#OA&
t;b1<TLn0
5;CqGzgoP
//获得文件长度 >>T,M@s-:
public long getFileSize() #Fckev4
{ B,4 3b O
int nFileLength = -1; jP31K{G?
try{ MZ:Ty,pw:O
URL url = new URL(siteInfoBean.getSSiteURL()); lGXr-K?+Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lFV\Go
httpConnection.setRequestProperty("User-Agent","NetFox"); Sd *7jW?
1B`JvNtd
^%t{:\
int responseCode=httpConnection.getResponseCode(); p?' F$Wz
if(responseCode>=400) ^0(`:*
{ q rF:=?`E
processErrorCode(responseCode); ;]VLA9dC
return -2; //-2 represent access is error bC,SE*F\
} "Z#MR`;&29
}_fVv{D
4Ix~Feuph
String sHeader; )(h<vo)-zX
c8oE,-~
+:3p*x%1H
for(int i=1;;i++) 6Tg'9|g
{ 5 J 7XVe>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !|-:"hE1h
//Utility.log(in.readLine()); g+QNIM>
sHeader=httpConnection.getHeaderFieldKey(i); J:dNV<A^
if(sHeader!=null) "u3 N9
{ M5`wfF,j
if(sHeader.equals("Content-Length")) v%)=!T,
{ 2#Y5*r's\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *n`8 -=
break; J@RV^2
} ?MD\\gN
} tg;AF<VI
else "9OOyeKu%
break; v03^
} ;5:3 =F>ao
} BFPy~5W
catch(IOException e){e.printStackTrace ();} Wl{wY,u
catch(Exception e){e.printStackTrace ();} kj@m5`G
QuBaG<
zvKypx
Utility.log(nFileLength); z<u@::
mU;\,96#
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return nFileLength; *?!A
} _))--+cL
Z`yW2ON$'
*W<|5<<u@
//保存下载信息（文件指针位置） Za'}26
private void write_nPos() eXQzCm
{ [p96H)8YU
try{ bX`VIFc
output = new DataOutputStream(new FileOutputStream(tmpFile)); ca"20NQ)
output.writeInt(nStartPos.length); Y4)=D@JI
for(int i=0;i<nStartPos.length;i++) 2^fSC`!
{ jEW@~e
// output.writeLong(nPos); qViolmDz
output.writeLong(fileSplitterFetch.nStartPos); to3D#9Ep
output.writeLong(fileSplitterFetch.nEndPos); KTjf2/
} _;u@xl=
output.close(); vLQh r&I
} O^4Ko}
catch(IOException e){e.printStackTrace ();} )5l9!1j
catch(Exception e){e.printStackTrace ();} QO3QR/Ww
} g({dD;
*!u a?
K2ry@haN
//读取保存的下载信息（文件指针位置） 8p.O rdp
private void read_nPos() "uD^1'IW2
{ Zl7m:b2M
try{ ym6gj#2m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); QE~#eo
int nCount = input.readInt(); wIK&EGQ
nStartPos = new long[nCount]; T^.W'
nEndPos = new long[nCount]; `YPNVm<3)
for(int i=0;i<nStartPos.length;i++) vY(xH>Fd
{ qh9Ix
nStartPos = input.readLong(); Z{ b($po
nEndPos = input.readLong(); ?iaD;:'qE
} S1W(]%0/
input.close(); Hh0a\%!
} ['_G1_p
catch(IOException e){e.printStackTrace ();} APY*SeIV
catch(Exception e){e.printStackTrace ();} ~ H $q
} Uv(Uj3D
,XmyC7y<
S`&YY89{&
private void processErrorCode(int nErrorCode) 4&^BcWqA*f
{ l;'c6o0e
System.err.println("Error Code : " + nErrorCode); :EZ"D#>y~
} +)-`$N
i>L>3]SRr{
Avi8&@ya
//停止文件下载 Wf:I 0
public void siteStop() e X q}0-*f
{ kV3Zt@+
bStop = true; /WE1afe_R
for(int i=0;i<nStartPos.length;i++) l} UOg
fileSplitterFetch.splitterStop(); 3bPF+(`J
$_NP4V8|z/
.+Fh,bNYK
} [";<YR7iRN
} J;cTEB
//负责部分文件的抓取 V-%Am
**FileSplitterFetch.java "+:~#&r
*/ 5b-: e? |
package NetFox; >$p|W~x
cQldBc
y}!}*Qj+/
import java.io.*; BjIKs~CT
import java.net.*; KsBi<wY
Z4@GcdZ
*WpDavovyB
public class FileSplitterFetch extends Thread { i& ybvTl
=)9@rV&~
1b-_![&]1
String sURL; //File URL a5# B&|#q
long nStartPos; //File Snippet Start Position U>s$}Y:+Z
long nEndPos; //File Snippet End Position [p# }=&d
int nThreadID; //Thread's ID 7iBN!"G0
boolean bDownOver = false; //Downing is over p@+r&Mg%W"
boolean bStop = false; //Stop identical a'2^kds
FileAccessI fileAccessI = null; //File Access interface #Jqa_$\.
o `N /w
?O<D&CvB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cN\Fgbt
{ {expx<+4F
this.sURL = sURL; 1C'_I
this.nStartPos = nStart; Z/hgr|&}
this.nEndPos = nEnd; \,5OPSB
nThreadID = id; 1O,<JrE+-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V,qc[*_3
} mh=YrDU+L
2RC|u?+@
P\R#!+FgW8
public void run() KWH l+pL
{ q2C._{ 0'
while(nStartPos < nEndPos && !bStop) wio}<Y6Xz
{ _]# ^2S
;VAHgIpx;
zwa%$U
try{ uWE :3
URL url = new URL(sURL); }L.&@P<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *c6o#[l
httpConnection.setRequestProperty("User-Agent","NetFox"); eAD uk!Iq
String sProperty = "bytes="+nStartPos+"-"; #N'W+M /
httpConnection.setRequestProperty("RANGE",sProperty); 1fzHmD
Utility.log(sProperty); l4+Bs!i`
t}]R0O.s
qoXncdDHZ
InputStream input = httpConnection.getInputStream(); ^yo~C3r~
//logResponseHead(httpConnection); >MeM
n6Qsug$z
^$I8ga
byte[] b = new byte[1024]; ckTk2xPQ
int nRead; 1SGLA"r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x<es1A'u6
{ MQ{.%
nStartPos += fileAccessI.write(b,0,nRead); o6[aP[~F
//if(nThreadID == 1) |kXx9vGq@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); at-+%e
} z[`OYwsW
-]K9sy)I
R#x~f
Utility.log("Thread " + nThreadID + " is over!"); Btgxzf
bDownOver = true; ~l@ h
//nPos = fileAccessI.write (b,0,nRead); NP#:} )
} kED1s's
catch(Exception e){e.printStackTrace ();} ^Voi4;
} B<" `<oG@|
} BrO" _
Dxlpo! ?#
:|tWKA
//打印回应的头信息 yHk}'YP
public void logResponseHead(HttpURLConnection con) \6)]!$F6:
{ tr t^o
for(int i=1;;i++) e 1$<,.>
{ aF41?.s
String header=con.getHeaderFieldKey(i); ,p\:Z3{ZH
if(header!=null) e(~9JP9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^L@2%}6b`
Utility.log(header+" : "+con.getHeaderField(header)); e: aa
else d~F4
break; .*(xkJI3
} 4Lb!Au|Y
} ~0 Ifg_G
hE|W%~Jx
&Q`{ Gk
public void splitterStop() G)G 257K"~
{ j@HOU~x
bStop = true; tvlrUp
} [ u.r]\[J
x[_SNX"
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} 'fIoN%
'C2X9/!,
s9)U",
/* #@3&1}J/
**FileAccess.java n,_q6/!
*//文件访问(定位，写) <Cbi5DtR
package NetFox; NrK.DY4
import java.io.*; Y*Ra!]62
<(c_[o/
5mYX#//:
public class FileAccessI implements Serializable{ iX|K4.Pz{
lPaTkZw
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;[-TsX:
RandomAccessFile oSavedFile; NtfzAz/
long nPos; aVvma=
Id}/(Pkq
{gkzo3
public FileAccessI() throws IOException EQTJ=\WFF
{ g]Jt (aYK
this("",0); w5+H9R6
} + ;LO|!
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5w+KIHhN|
public FileAccessI(String sName,long nPos) throws IOException r&y0`M
{ 31^Jg
oSavedFile = new RandomAccessFile(sName,"rw"); tSVWO]<
this.nPos = nPos; =f/CBYNw@V
oSavedFile.seek(nPos); iLC.?v2=
} dtT:,&
@y!oKF
Mm)yabP
public synchronized int write(byte[] b,int nStart,int nLen) !y\r.fm!A
{ L}a-c(G+8
int n = -1; &pzf*|}
try{ }NJKkj?
oSavedFile.write(b,nStart,nLen); 'w z6Zt
n = nLen; 1]A$
} !*1$j7`tP
catch(IOException e) o"!C8s_6
{ XU y[l
e.printStackTrace (); e~U]yg5X-
} ZQk!Ia7
@=sM')f&
2<FEn$n[
return n; 2z9s$tp
} {MV,>T_
?Qxf~,F
FMi:2.E
} HSk_'g(\0
2Onp{,'}
:o 8XG
/* S54q?sb_
**SiteInfoBean.java TtQ'I}7q
*/ 2O 2HmL
package NetFox; 21$E.x 6
nSv@FT'~z
D"V(A\sZ
public class SiteInfoBean { 7tbY>U8
Yu$QL@
`y|_hb
private String sSiteURL; //Site's URL Uv m:`e~?
private String sFilePath; //Saved File's Path ZXIw^!8@/
private String sFileName; //Saved File's Name oo\7\b#Jx
private int nSplitter; //Count of Splited Downloading File $<QrV,T
d%za6=M
bFIM07
public SiteInfoBean() 9{wRqY
{//nSplitter的缺省值为5 [=BccT:b
//default value of nSplitter is 5 o(k{Ed
this("","","",5); VIHuo,
} F[v:&fle
BW:HKH.k
>qz#&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q+oV? S3{
{ JC MUK<CG
sSiteURL= sURL; V3>tW,z
sFilePath = sPath; hUC157
sFileName = sName; BsU}HuQZQ
this.nSplitter = nSpiltter; ,v<7O_A/e
]rG/?1'^i
/9e?uC6
} n$F~
Fw S>V2R
uGv|!UQw
public String getSSiteURL() {Q}F.0Q
{ L>h|1ZK
return sSiteURL; N;`/>R4|I
} B[I9<4}
?<`oKBn
z2>LjM) #
public void setSSiteURL(String value) [l3ys
{ $nb.[si\
sSiteURL = value; 6w=`0r3hy
} -&COI-P8
XEnu0gr
W=#AfPi$&
public String getSFilePath() }T0O~c{$i
{ PY;tu#W!%
return sFilePath; Khb Ku0Z
} AhD C5ue=
dU#-;/}o
CLTkyS)C
public void setSFilePath(String value) ;=7K*npT
{ V)5K/U{
sFilePath = value; *a\6X( ~
} 9O-2
m):*>o55
!> =ybRe
public String getSFileName() 64mg:ed&
{ 8IA1@0n&
return sFileName; lLp,sNAj
} :r@t'
`% QvCAR
D<m0G]Ht*
public void setSFileName(String value) c"v75lW-J
{ *i}X(sfe
sFileName = value; .L+XV y
} wk ^7/B
{fnx=BaG
c:.~%AJx
public int getNSplitter() ^nK<t?KS
{ x9,jXd
return nSplitter; .[}G{%M~[
} F#>00b{Q
{vGJ}q?Sd"
+U1 Ir5Lx
public void setNSplitter(int nCount) a%e`
{ e{7\pQK
nSplitter = nCount; Bb:C^CHIQm
} qa-FLUkIk!
} r=&,2meo
4 sax
'w27Lt'V
/* ni&|;"Nt-
**Utility.java #]x3(}3W
*/ VJ=>2'I
package NetFox; kDE-GX"Y
~\mh\a&
i1|>JM[V
public class Utility { +4.s4&f)
#D4
{BmqUoZrC
public Utility() G.H8 ><%
{ T#H^ }`
!uQT4<g
^3TNj
} N(Ru/9!y"
Lxwi"ndP
//线程睡眠 |82q|@e
public static void sleep(int nSecond) 1!KROes4
{ ~PI2G9
try{ E?G'F3i
Thread.sleep(nSecond); J7* o%W*V
} X58U>4a
catch(Exception e) 4%^z=%
{ {_Wrs.a'8
e.printStackTrace (); *^uK=CH1?(
} n&njSj/
} W48RZghmx
RkE)2q[5
//日志 Ln4]uqMG.
public static void log(String sMsg) _Xt/U>N
{ 16zReI(
System.err.println(sMsg); V9,<>
} 8i154#l+\
dMH_:jb
GLn=*Dh#
public static void log(int sMsg) r*+~(83k
{ .`}TND~
System.err.println(sMsg); 9h amxi
} q1T)H2S
} ->rqr#
{5~h
F(yR\)!C
/* 68XJ`/d
**TestMethod.java c|k_[8L
*/ Cgx:6TRS
package NetFox; k1<^Ept
`Pvi+:6\Y
8f9wUPr
public class TestMethod { Hw o _;fV
LUbj^iQ9
DjM*U52Yfj
public TestMethod() sfyLG3$/
{ ///xx/weblogic60b2_win.exe LN|(Z*
try{ He(65ciT<O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); { c#US
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y(g_h:lf,]
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z 2N6r6
fileFetch.start(); Vr EGR$
} w$:\!FImx
catch(Exception e){e.printStackTrace ();} gx.\H3y
In1W/?
;OlnIxH(W
} 1'qXT{f/~
k( :Bl
6G2~'zqPc~
public static void main(String[] args) <D/K[mz-
{ >qo!#vJc a
new TestMethod(); ?6CLUu|7n
} R iLl\S#
} '#7k9\
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