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)); w^G<]S{l
} O:xRUjpL
for(int i=0;i<nEndPos.length-1;i++) )w;XicT
{ q6H90Zb
nEndPos = nStartPos[i+1]; t+m$lqm
} aWOApXJ
nEndPos[nEndPos.length-1] = nFileLength; ^YenS6`F
} ~`T(mh',
} ZzzQXfA#
iknBc-TLD
)3h=V^rm
//启动子线程 Q&`$:h.~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; qIA!m .GC
for(int i=0;i<nStartPos.length;i++) f IQ$a>
{ p8Lb*7W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )"t=sFxaB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bC?t4-W
nStartPos,nEndPos,i); wC@4`h\U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :ozHuHJ#
fileSplitterFetch.start(); D~NH 4B
} dfc-#I p?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f`/JY!uj{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;P5\EJo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [rqq*_eB
nEndPos = " + nFileLength); H'?Bx>X
// fileSplitterFetch[nPos.length-1].start(); -("79v>#
Pa0tf:
|=N8X
//等待子线程结束 s67$tlV
//int count = 0; ;Qk*h'}f
//是否结束while循环 Rp}6}4=d
boolean breakWhile = false; Yfxc$ub
Mgcq'{[~Y=
k5g\s9n]
while(!bStop) ;&Eu<%y
{ |=jgrm1yj
write_nPos(); p_B,7@Jl
Utility.sleep(500); gOgG23 x
breakWhile = true; $'?CY)h{
jpm}EOq<%
VaVKWJg$
for(int i=0;i<nStartPos.length;i++) rIW`(IG_
{ ;X|;/@@
if(!fileSplitterFetch.bDownOver) zr84%_^
{ *v l_3S5_
breakWhile = false; dr,j~s
break; 3~s0ux[
} m]7Y )&3
} cCyg&% zsT
if(breakWhile) qLA
break; 6tzZ j:yq
Ujq)h:`
FE/&<g0,:
//count++; (5_oH
//if(count>4) AWD &K!
// siteStop(); {\C$Bz
} Ls*.=ARq
GlQ=M)E
;bP7|
System.err.println("文件下载结束！"); |06J4H~k
} zrnc~I+
catch(Exception e){e.printStackTrace ();} clG3t eC
} 4sNM#]%|
4J94iI>S.l
OSfwA&
//获得文件长度 Dih~5
public long getFileSize() RM%lhDFY
{ PeTA:MW
int nFileLength = -1; iO<O2A.F
try{ ^h^j:!76j
URL url = new URL(siteInfoBean.getSSiteURL()); +n2x@ 0op
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;E*^AW
httpConnection.setRequestProperty("User-Agent","NetFox"); 9L!Vj J
4.H!rkMM
``aoLQc`
int responseCode=httpConnection.getResponseCode(); 47$JN}qI0
if(responseCode>=400) >s[}f6*2@
{ c{||l+B
processErrorCode(responseCode); +1h^9Y'
return -2; //-2 represent access is error bTHJbpt*-
} GN=F-*2
?em)om
<KHB/7
String sHeader; O}IS{/^7
F^A1'J
+/x|P-
for(int i=1;;i++) ~X`vRSrH
{ _IT,>#ba
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8b6:n1<fn
//Utility.log(in.readLine()); F^`sIrZvs
sHeader=httpConnection.getHeaderFieldKey(i); P5] cEZ n
if(sHeader!=null) g&_0)(a\
{ -bo0!@MK
if(sHeader.equals("Content-Length")) a`/[\K6
{ EMs$~CL4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kIXLB!L2b^
break; ;qG a|`#j
} LoBKR c2t
} L d#
else 9&rn3hmP
break; b-~`A;pr
} :4(7W[r6
} mUnnk`v
catch(IOException e){e.printStackTrace ();} yKDg ~zsh
catch(Exception e){e.printStackTrace ();} 2Q1* Xq{
Zh3]bg5
3bE^[V8/
Utility.log(nFileLength); VMHiuBz:
$5il]D`
}"q1B
return nFileLength; 0qR;Z{k
} W{Nhh3
'-W p|A
]Ms~;MXlx5
//保存下载信息（文件指针位置） zg8m(=k'
private void write_nPos() IXd&$h]Lq
{ ~jF5%Gu
try{ |$bZO`^
output = new DataOutputStream(new FileOutputStream(tmpFile)); |6_<4lmTxF
output.writeInt(nStartPos.length); pjbKMx
for(int i=0;i<nStartPos.length;i++) _|*3uGo:
{ 6 D!,vu
// output.writeLong(nPos); ;]<$p[m
output.writeLong(fileSplitterFetch.nStartPos); mRQ F5W6
output.writeLong(fileSplitterFetch.nEndPos); .0\Wu+
} y6:=2(]w<p
output.close(); Q?[k>fu0
} Z~$&h
catch(IOException e){e.printStackTrace ();} {H"gp?Z-
catch(Exception e){e.printStackTrace ();} 7(gQ6?KsZ
} i3(bg,
d&R/fIm
ce+\D'q[
//读取保存的下载信息（文件指针位置） iW)FjDTP
private void read_nPos() vcV=9q8P1
{ &?zJ|7rh@|
try{ @iWIgL
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p?Yovckm
int nCount = input.readInt(); &Hh%pY"
nStartPos = new long[nCount]; (`>4~?|+T
nEndPos = new long[nCount]; 27,WP-qie
for(int i=0;i<nStartPos.length;i++) U R@'J@V#:
{ 2!&:V]
nStartPos = input.readLong(); ,$}v_-:[l
nEndPos = input.readLong(); u\=Nu4)Z F
} kFuaLEJi
input.close(); gI\J sN
} 3+n&Ya1
catch(IOException e){e.printStackTrace ();} 8a-[Q
catch(Exception e){e.printStackTrace ();} A!iV iX &y
} Q6}`%
of{wZU\J+9
8?I(wn
private void processErrorCode(int nErrorCode) LuQ=i`eXx
{ /!7m@P|&D
System.err.println("Error Code : " + nErrorCode); B;7L:
} #C!8a
#kma)_X
m"+9[d_u
//停止文件下载 O a-ZeCq
public void siteStop() 9"MC<
{ E;-R<X5n
bStop = true; |y;+xEl6
for(int i=0;i<nStartPos.length;i++) "d.qmM
fileSplitterFetch.splitterStop(); 6S`eN\s
+-8uIqZ
pN%L3?2
} >rYP}k
} ]u2!)vZh'
//负责部分文件的抓取 h-jea1m
**FileSplitterFetch.java G4<'G c
*/ ;QgJw2G
package NetFox; ^>k[T.
wU+ofj; +I
m_(+-G
import java.io.*; WW==
import java.net.*; =xa`)#4(
:X2B+}6_&
c&F"tLl
public class FileSplitterFetch extends Thread { >@y5R^B`
. 6Bz48*
S ._9
String sURL; //File URL 7,Z%rqf\)
long nStartPos; //File Snippet Start Position G}f.fRY
long nEndPos; //File Snippet End Position H!oP!rzEo
int nThreadID; //Thread's ID y4M<L. RO
boolean bDownOver = false; //Downing is over pD`7N<F 3
boolean bStop = false; //Stop identical Ng+k{vAj
FileAccessI fileAccessI = null; //File Access interface bU_9GGG|
5=Gq d4&*
=@{H7z(p&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W13$-hf9
{ UY)YhXW
this.sURL = sURL; *^" 4 )
this.nStartPos = nStart; fn;7Nf7{
this.nEndPos = nEnd; ZJ+q<n_4}
nThreadID = id; Mb?6c y[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bk#u0N
} Pi)`[\{
ot-!_w<
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public void run() "R):B~8|H{
{ xE4T\%-K
while(nStartPos < nEndPos && !bStop) g-')|0py
{ {-<h5_h@
2eb :(D7Cq
{kW!|h&'
try{ rj<%_d'Z`
URL url = new URL(sURL); #i:p,5~")
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uX`Jc:1q3
httpConnection.setRequestProperty("User-Agent","NetFox"); Cw Z{&
String sProperty = "bytes="+nStartPos+"-"; yUEUIPL
httpConnection.setRequestProperty("RANGE",sProperty); {b]WLBy
Utility.log(sProperty); d \0K3=h
JLc\KVmF
S>cT(q_&
InputStream input = httpConnection.getInputStream(); Rn-L:o@?
//logResponseHead(httpConnection); Zf(ucAhL
8]2S'mxE
#M{}Grg
byte[] b = new byte[1024]; 4S03W
int nRead; 1N:eM/a
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O6boTB_2
{ 6OIA>%{
nStartPos += fileAccessI.write(b,0,nRead); 7jEAhi!Cq(
//if(nThreadID == 1) Z@~8iAgE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W&Fa8
} <8jn_6
3H4p$\;C
+J.^JXyp0
Utility.log("Thread " + nThreadID + " is over!"); 5l{_E:.1
bDownOver = true; 51&wH
//nPos = fileAccessI.write (b,0,nRead); 1v,4[;{
} N"HN]Y@w
catch(Exception e){e.printStackTrace ();} c5O1h8
} B>9D@fmzs
} bjD0y cB[
Xo]FOJ5
d{9jd{ _#G
//打印回应的头信息 6,cyi|s
public void logResponseHead(HttpURLConnection con) gsT%_2>CL
{ 0=-h9W{zI
for(int i=1;;i++) dd98vVj
{ yK[~(!c5
String header=con.getHeaderFieldKey(i); sowkxw.^Q
if(header!=null) PJkEBdM.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o7hjx hmC
Utility.log(header+" : "+con.getHeaderField(header)); ))306*X\
else o.y4&bC14;
break; F+c*v#T
} ) VJ|
} {e>}.R
5UjXpS
{^$rmwN
public void splitterStop() {?eD7xL:-
{ `q4\w[0+p
bStop = true; Lo9+#ITyx
} _(oJ8h(
kdgQ -UN$
3#5sj >
} lC^q}Bh:
VI37
>f}rM20Vm
/* cAIS?]1
**FileAccess.java W 4 )^8/
*//文件访问(定位，写) O:k@'&
package NetFox; ]6}|X#_
import java.io.*; F<G.!Y8!&
z[CCgs&vqe
s}/YcUK
public class FileAccessI implements Serializable{ M62V NYt
.VWH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >/evL /
RandomAccessFile oSavedFile; ) ~ C)4
long nPos; wK|&[ms
x!LUhX '
<fN?=u+
public FileAccessI() throws IOException u3"F7 lJ
{ X8?|5$Ey
this("",0); 4sROMk=l
} 0'aZ*ozk
uXtfP?3Vy
=C5[75z#+
public FileAccessI(String sName,long nPos) throws IOException `Mp]iD{
{ 8 rnr>Ee@
oSavedFile = new RandomAccessFile(sName,"rw"); "f5u2=7 }
this.nPos = nPos; VZw("a*TB
oSavedFile.seek(nPos); >;0z-;k6
} 4[rD|
9u"im+=:
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public synchronized int write(byte[] b,int nStart,int nLen) Z#^2F8,]
{ _mFb+8C
int n = -1; 21w<8:Vg
try{ I"Y?vj9]
oSavedFile.write(b,nStart,nLen); A}[Lk#|n
n = nLen; /T*{Mo{B
} vC+mC4~/(
catch(IOException e) Q7`zrCh
{ .8fOc.h8h
e.printStackTrace (); W6~<7
} ou96 P<B
Gz^g!N[
24|:VxO
return n; kD"dZQx
} wBCnP
f)N67z6
@CWfhc-Ub
} 'pZ~3q
~hP[[?
]Jv Z:'g}
/* .L6t3/^
**SiteInfoBean.java 7.akp
*/ )M^;6S
package NetFox; b]CJf8'u
M`iJ6L
qfN<w&P
public class SiteInfoBean { vWzNsWPK"{
PMkwY{.u
zgVplp
private String sSiteURL; //Site's URL NL2n\%n
private String sFilePath; //Saved File's Path r}03&h~Hc&
private String sFileName; //Saved File's Name :tR%y"
private int nSplitter; //Count of Splited Downloading File zXZy:SD
:sM|~gT
("mW=Ln
public SiteInfoBean() h7(twct
{//nSplitter的缺省值为5 t1IC0'o-
//default value of nSplitter is 5 HHtp.;L/
this("","","",5); JEFW}M)UGv
} 0#<_:E
EL~s90C
; Sh|6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f~W.i]
{ '6 w|z^
sSiteURL= sURL; zCPjuS/~ Q
sFilePath = sPath; 1NJ*EzJ~?
sFileName = sName; Ya\G/R
this.nSplitter = nSpiltter; _%<7!|"
8v(Xr}q,r
Na3tK}x
} :UFf6T?
w_A-:S 5C
AGrGZ7p]
public String getSSiteURL() lywcT! <
{ =>-b?F0(c
return sSiteURL; Zj`eR\7~
} TX;OA"3=\-
%'^m6^g;
.8.ivfmJh
public void setSSiteURL(String value) )@))3
{ ?86h:9
sSiteURL = value; Bg7?1m
} <J`_Qc8C
{"4t`dM
9chiu%20
public String getSFilePath() AS4m227
{ a$;+-Y
return sFilePath; :gQc@)jZ(*
} kl2]#G(
x40R)Led
Mzxz-cE
public void setSFilePath(String value) MZ0uc2L=
{ 0r+-}5aSl5
sFilePath = value; d7KeJ$xy}p
} y0A2{'w
Z AZQFr'*
?6uh^Qal
public String getSFileName() oqE h_[.
{ 2LD4f[a;
return sFileName; ) e;F@o3
} j-yD;N
MZL~IX
/[{?zS{
public void setSFileName(String value) Td8'z'
{ t(}&<<1Bz
sFileName = value; wiwJD}3h'
} j|+B|
r("7 X2f
Wy4v~]xd%
public int getNSplitter() ~zYp(#0op
{ 'HOcK8}b
return nSplitter; E*RP8
} hkW"D<ii-
T 0^U ]C
q+)KY
public void setNSplitter(int nCount) ,QG,tf?
{ Z/Mp=273
nSplitter = nCount; Za=<euc7
} :Z1_;`>CT
} yd>kJk^~/
Z\dILt:#z
lzm9ClkfH
/* Or6'5e?N
**Utility.java 9';0vrFeM
*/ ts9N$?0:V
package NetFox; %>24.i"l
fI"`[cA"]
CGv(dE,G&]
public class Utility { [nG/>Z]W
iW |]-Ba\
Az0Yt31=
public Utility() C5XCy%h
{ M~ *E!
hoU&'P8
94K;=5h
} (y(V,kXwa8
oZOFZ-<
//线程睡眠 *sL'6"#Cre
public static void sleep(int nSecond) CR, Y%0vQ
{ a?+) K
try{ wBeOMA
Thread.sleep(nSecond); 3zh'5qQ
} kTFN.kQx@
catch(Exception e) 1u&P,&T
{ P#EqeO
e.printStackTrace (); 'n>|jw)
} %f:'A%'Qb
} g:f0K2)\r:
q:?g?v
//日志 0imz}Z]
public static void log(String sMsg) uy`U1>
{ S6]D;c8GE
System.err.println(sMsg); 's&Vg09D,
} '*)!&4f
U?>zq!C&R
V(w[`^I>~
public static void log(int sMsg) ^P{'l^CVX
{ *23
System.err.println(sMsg); q)@.f.
} R` X$@iM
} .cu5h
9N'$Y*. d<
CQv [Od
/* -R&h?ec
**TestMethod.java b_wb!_
*/ %lV>Nc|iz=
package NetFox; .h7b 4J
sav2.w
MfYe @;m
public class TestMethod { 1noFXzeU3
fcV/co_S6
[5m;L5
public TestMethod() ?*4]LuK6
{ ///xx/weblogic60b2_win.exe LO` (V
try{ ef,6>xv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); x/9`2X`~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); - MBK/
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~zRW*pd
fileFetch.start(); ?BWWb
} 3QXGbu}:h!
catch(Exception e){e.printStackTrace ();} KTf!Pf?g
2etlR
7:1Hgj(
} ?m~x%[Vn
zGz5|u
SM^6+L"BE
public static void main(String[] args) y()#FRp7
{ .Hgiru&
new TestMethod(); kxf'_Nzy
} A:p0p^*
} VQ}=7oe%q
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