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)); &ZHC-qMRK
} )}%O>%
for(int i=0;i<nEndPos.length-1;i++) wXjFLg!g?
{ ^E`(*J/o
nEndPos = nStartPos[i+1]; fQK"h
} -~" :f8
nEndPos[nEndPos.length-1] = nFileLength; nR>r2wMk@
} X6+qpp
} (UCK;k
)+")Sz3zx
5l-mW0,MK
//启动子线程 ]j~"mFAP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^>y@4qB
for(int i=0;i<nStartPos.length;i++) Z BUArIC
{ sAJ7R(p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )&{K~i;:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lOwS&4UT
nStartPos,nEndPos,i); R=Ws#'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y;?ie]3G
fileSplitterFetch.start(); q}BzyC=:n
} +z9@:L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %Pqk63QF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l=N2lHU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", raVA?|'g~
nEndPos = " + nFileLength); D0(xNhmKz
// fileSplitterFetch[nPos.length-1].start(); ;;$#)b
C${S^v
'\fY<Q:!
//等待子线程结束 %n%xR%|
//int count = 0; PfS:AIy
//是否结束while循环 tj]9~eJ-
boolean breakWhile = false; ZlYPoOq
Cd79 tu|
;Yfv!\^|
while(!bStop) -7uwOr
{ [OTJVpC
write_nPos(); b*fgv9Kh'
Utility.sleep(500); lDC$F N
breakWhile = true; R`";Z$~{
;R=.iOn
BG^C9*ZuP
for(int i=0;i<nStartPos.length;i++) "1q>At
{ $P7iRM]
if(!fileSplitterFetch.bDownOver) j6~nE'sQ
{ :M{Y,~cP
breakWhile = false; qzw'zV
break; !J*,)kRN
} {HC@u{K-
} %u^JpC{E
if(breakWhile) -5>-%13
break; wfL-oi'5
8E&XbqP+
uJR%0E7!
//count++; U`Jy!x2m
//if(count>4) thO ~=RB
// siteStop(); Ko&hj XHx
} .I VlEG0
3bqC\i^[\m
N!Qg;(
System.err.println("文件下载结束！"); WD;Y~|
} z)XRx:YU;$
catch(Exception e){e.printStackTrace ();} < _$%@4 L
} FEPXuCb
Glq85S
]nQt>R p_
//获得文件长度 r!P}u
public long getFileSize() 2>-S-;i
{ p2J|Hl|
int nFileLength = -1; UY2X
try{ $wYtyN[
URL url = new URL(siteInfoBean.getSSiteURL()); {Y}dv`G#Iu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aw?=hXR!
httpConnection.setRequestProperty("User-Agent","NetFox"); =z{JgD/
+5.t. d
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int responseCode=httpConnection.getResponseCode(); E|YdcS
if(responseCode>=400) ]Mj/&b>"e
{ Sp}D;7
processErrorCode(responseCode); vhvdKD
return -2; //-2 represent access is error vQF vtwd
} GEjd7s]C
VKm!Ri$
FVv8--
String sHeader; !|2VWI}
.t&R>9cZ^
Mfk2mIy
for(int i=1;;i++) T,fI BD:
{ Tj~IaU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1[*UYcD
//Utility.log(in.readLine()); *'"T$ib
sHeader=httpConnection.getHeaderFieldKey(i); H4OhIxK
if(sHeader!=null) T9 <2A1
{ ,U*)2`[
if(sHeader.equals("Content-Length")) Y=Z1Tdxa|
{ 'tN25$=V&W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iDl;!b&V.
break; AeIrr*~]B
} Vh3Ijn
} &Gm$:T'~
else +,:^5{9{
break; ?::NO Dg
} w(L>#?
} ^1:U'jIXO
catch(IOException e){e.printStackTrace ();} oIGrA-T}
catch(Exception e){e.printStackTrace ();} c/L>>t
=H0vE7{*
#{r#;+
Utility.log(nFileLength); e@@?AB$n(
A392=:N+Q
%2'A pp
return nFileLength; S1n3(U:m
} j4FeSGa
Lf:uNl*D
oHM ]
//保存下载信息（文件指针位置） *O:r7_ Y0
private void write_nPos() :ztr)
{ h@7FY
try{ ?^' 7+8C*J
output = new DataOutputStream(new FileOutputStream(tmpFile)); UE _fpq
output.writeInt(nStartPos.length); dAP|:&y@
for(int i=0;i<nStartPos.length;i++) 2LCB])X
{ M)?dEgU}M
// output.writeLong(nPos); ~mV"i7VX
output.writeLong(fileSplitterFetch.nStartPos); g#NZ ,~
output.writeLong(fileSplitterFetch.nEndPos); _a_xzv'
} YL jHt\
output.close(); H@X oqgI
} _!xD8Di#
catch(IOException e){e.printStackTrace ();} gB\T[RV
catch(Exception e){e.printStackTrace ();} UX`]k{Mz
} EG'[`<*h
-]Cc
gw+9x<e
//读取保存的下载信息（文件指针位置） e73^#O&Xt
private void read_nPos() d{et8N
{ ogM%N
try{ E{=2\Wkcp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _2fkb=2@
int nCount = input.readInt(); 0,*%vG?Q
nStartPos = new long[nCount]; qP!eJ6[Nh"
nEndPos = new long[nCount]; P ]N [y
for(int i=0;i<nStartPos.length;i++) Jxf~&!zR
{ w)E@*h<Z
nStartPos = input.readLong(); VS#wl|b8
nEndPos = input.readLong(); QYXx:nIrg
} I~PDaZP
input.close(); B}OY/J/*8
} Gx?+9CV
catch(IOException e){e.printStackTrace ();} DPe]daF
catch(Exception e){e.printStackTrace ();} ^x*nq3^h\
} ?[ly`>KpJ
D/(L
RVtQ20e";r
private void processErrorCode(int nErrorCode) -@^Zq}
{ (VyNvB
System.err.println("Error Code : " + nErrorCode); mtic>
} U5Erm6U:
Ot&:mT!2
YF#HSf7
//停止文件下载 F0~k1TDw
public void siteStop() g1(Xg.
{ ]!1OH |Ad
bStop = true; +ww^ev%
for(int i=0;i<nStartPos.length;i++) ||2Q~*:
fileSplitterFetch.splitterStop(); hf!|\f
qv 3^5d
G DSfT{kK\
} ,F+B Wot4
} N;F)jO xsl
//负责部分文件的抓取 \^+ILYO:$
**FileSplitterFetch.java `|1MlRM9
*/ ocwG7J\W
package NetFox; N5|Rmfo1
#)+- lPe
fnzy5+9"
import java.io.*; s*M@%_A?
import java.net.*; 9D@$i<D:
PDx)S7+w[
fLN!EDq
public class FileSplitterFetch extends Thread { ,Y_{L|:w
C>^D*C(
{ PlK@#UN
String sURL; //File URL (%ew604X
long nStartPos; //File Snippet Start Position X{Yw+F,j
long nEndPos; //File Snippet End Position >QQ(m\a$
int nThreadID; //Thread's ID KYJ1}5n
boolean bDownOver = false; //Downing is over (lA.3 4.p
boolean bStop = false; //Stop identical VCNT4m
FileAccessI fileAccessI = null; //File Access interface Mro4`GL
gLD`wfZR
{!ZyCi19
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^jdL@#k00
{ |wxGpBau
this.sURL = sURL; ~KjJ\b)R
this.nStartPos = nStart; ;:&?=d
this.nEndPos = nEnd; ,reJ(s
nThreadID = id; ~ <0Z>qr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :L?_Y/K
} FD7H@L5
}pNX@C#De
Ftb%{[0}u3
public void run() P=AS>N^yaL
{ $*MCUnl
while(nStartPos < nEndPos && !bStop) 2)iD4G`
{ uE_c4Hp
ZU'!iU|8
KV!<Oq
try{ AWr}"r?s
URL url = new URL(sURL); =Cf]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); db=$zIB[:
httpConnection.setRequestProperty("User-Agent","NetFox"); qG8s;_G
String sProperty = "bytes="+nStartPos+"-"; r >{G`de4
httpConnection.setRequestProperty("RANGE",sProperty); 0V,Nv9!S
Utility.log(sProperty); )yee2(S
Y,z??bm~J
4k}e28
InputStream input = httpConnection.getInputStream(); -Q e~)7
//logResponseHead(httpConnection); 4|J[Jdj
;~ 4k7Uz
SDJH;c0
byte[] b = new byte[1024]; Pd=,$UQp
int nRead; aA*9,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l4'~}nn(Y
{ >}+Q:iNQ)2
nStartPos += fileAccessI.write(b,0,nRead); f*((;*n;
//if(nThreadID == 1) hAR? t5c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S*W;%J5
} 0O@_cW
n"{X!(RIcx
kka"C]!
Utility.log("Thread " + nThreadID + " is over!"); 7 &)]) {Q
bDownOver = true; >O{7/)gS^
//nPos = fileAccessI.write (b,0,nRead); #mc!Wt10
} %n$^-Vc&
catch(Exception e){e.printStackTrace ();} {gF0Xm%
} <dR,'
} 0`hwmDiB"
[5ethM
B:oF;~d/,
//打印回应的头信息 I@7/jUO
public void logResponseHead(HttpURLConnection con) r((Tavn
{ _j#SpL'P
for(int i=1;;i++) wvc>0?t'
{ '8Wv.X0`
String header=con.getHeaderFieldKey(i); _."E%|5
if(header!=null) ,TC~~EWq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y>o>WN<q
Utility.log(header+" : "+con.getHeaderField(header)); $%qg"
else E{^^^"z P
break; :xeLt;
} *_hLD5K!
} J%v5d*$.
GG-[`!>.pw
W?,$!]0
public void splitterStop() W|c.l{A5Q
{ gp
bStop = true; 6vz1*\:H~
} Q|hm1q
-e>|kPfv!
Agy <j
} )^;DGzG
L@)&vn]
<)#kq1b?
/* %]4-{%v
**FileAccess.java \ElX~$fS
*//文件访问(定位，写) O]=C#E{
package NetFox; ?C;JJ#Ho
import java.io.*; D[Iqn
u}jrfKdE
2"/yEg*=
public class FileAccessI implements Serializable{ 7 ^I:=qc72
ey1Z/|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5{l1A(b
RandomAccessFile oSavedFile; :$H!@n*/R
long nPos; k$[{n'\@
'F_}xMU
}=@zj6AC
public FileAccessI() throws IOException D1"7s,Hmu
{ /8eW@IO.F
this("",0); C ?7X"~~
} b~Z=:'m8
D s-`
y4F^|kS) [
public FileAccessI(String sName,long nPos) throws IOException gg]~2f
{ -J$g(sikt
oSavedFile = new RandomAccessFile(sName,"rw"); 7kz-V.
this.nPos = nPos; 960qvz!
oSavedFile.seek(nPos); :m`/Q_y"
} gue(C(~.k_
1L[S*X
MW@DXbKVl
public synchronized int write(byte[] b,int nStart,int nLen) XVUf,N,
{ N/{?7sG&
int n = -1; -<oZ)OfU
try{ 7:o+iP46
oSavedFile.write(b,nStart,nLen); v]bAWo
n = nLen; f=ib9WbR#
} TETsg5#
catch(IOException e) .hN3`>*V
{ h~ha
e.printStackTrace (); rSyaZ6#
} zqGYOm$r
|=3 *;}
;nk@XFJ
return n; |~NeB"l{
} X<xqT
878tI3-
h)o]TV
} u2lmwE
FmA-OqEpA
c!D> {N
/* Zr"dOj$Jf
**SiteInfoBean.java (3fPt;U
*/ v*DFiCQD
package NetFox; TNci.']
*/U$sZQ)
6y@<?08Q
public class SiteInfoBean { iEhDaC[e(b
Yq;&F0paK
MVAc8dS
private String sSiteURL; //Site's URL ,k%8yK
private String sFilePath; //Saved File's Path '3%*U*I
private String sFileName; //Saved File's Name Oxn'bh6R0
private int nSplitter; //Count of Splited Downloading File 4TJ!jDkox
r,nn~
,4Y sZ
public SiteInfoBean() 1UyH0`&
{//nSplitter的缺省值为5 CjZ6NAHc
//default value of nSplitter is 5 '#f?#(
this("","","",5); ~~dfpW_"
} IMR$x(g= F
nO [QcOf
nDn{zea7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KgU[
{ j?J=w=.Nx
sSiteURL= sURL; ^K>pT}u
sFilePath = sPath; Na;t#,
sFileName = sName; N[{]iQ
this.nSplitter = nSpiltter; D[W}[r
2$Y3[$
K!b>TICa:
} 6cZ C
"0Y&~q[=
"GBUQ}
public String getSSiteURL() g{&PrE'e9
{ QQ|9>QP
return sSiteURL; ;S=e%:zb
} A'v[SUW'm
_Fvsi3d/
XAlD ww
public void setSSiteURL(String value) EM~7#Y
{ e)og4
sSiteURL = value; % NwoU%q
} Ug`
%J3lK]bv(
A3!2"}L
public String getSFilePath() $YR{f[+L w
{ oG9SO^v_
return sFilePath; D2-O7e
} <v-92?
"lb\c
&:,fb]p
public void setSFilePath(String value) dW6Q)Rfi
{ "p2u+ 8?
sFilePath = value; KKMWD\
} n]Ebwznt-
-*5yY#fw}
C890+(D~
public String getSFileName() E<P*QZ-C3
{ 4t(QvIydA
return sFileName; F6h/0i
} 0MhxFoFO
J2x$uO{Bn
c{ZqQtfM
public void setSFileName(String value) :4b- sg#
{ m R"9&wq
sFileName = value; ]n/jJ_[
} m';|}z'
JCBnFrP
,9+nfj
public int getNSplitter() *+# k{D,
{ T)*l' g'
return nSplitter; %hrsE5k^,
} RH1U_gp4 ]
KN|'|2/|
9yp^zL
public void setNSplitter(int nCount) EzwF`3RjK
{ aw;{<?*
nSplitter = nCount; ZW`HDrP`
} LIc*tsl
} F\l!A'Q+t
ZlUFJ*pk
I\)N\move
/* +# A|Zp<
**Utility.java jh-kCF
*/ mRNHq3
package NetFox; "otr+.{`*
FkLQBpp(x
O{O9}]6
public class Utility { 7Co3P@@
6YB-}>?
~6=Wq64
public Utility() %,h!: Ec^c
{ ~p0e=u
E%KC'TN^D
1"N/ZKF-x
} 30:HRF(:
6!i( \Q*
//线程睡眠 h/w]
public static void sleep(int nSecond) 4ZSfz#<[z
{ K4BTk!
try{ iFXUKGiV
Thread.sleep(nSecond); 4d,qXSKty
} h:eN>yW
catch(Exception e) qLU15cOM
{ Ul7,k\q@
e.printStackTrace (); ||bA
} 3ytx"=B%
} 5QCw5N
F^J&g%ql
//日志 0fEZD$
public static void log(String sMsg) xow6@M,
{ dpl"}+
System.err.println(sMsg); Vu^Q4Z
} 2*b#+b
!^rITiy
gt(X!iN]
public static void log(int sMsg) Ss*LgK_
{ R A-^!4tX
System.err.println(sMsg); ~M|NzK_9
} 89?3,k
} `XFX`1
=+kvL2nx-
HQjxJd5P
/* _CYmG"mY
**TestMethod.java Y,p2eAss
*/ exGhkt~
package NetFox; +sV#Z,
4'7 v!I9
#w[q.+A
public class TestMethod { _Y:Ja0,
+Px<DX+
U:C-\ M
public TestMethod() fbW,0
{ ///xx/weblogic60b2_win.exe woC FN1W
try{ mRix0XBI~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z)b)v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?et0W|^k
SiteFileFetch fileFetch = new SiteFileFetch(bean); OdtbVF~
fileFetch.start(); !ds"88:5^
} 1VPfa
catch(Exception e){e.printStackTrace ();} t/EMBfLc
o)$Q]N##
tOp:e KN
} ZKiL-^dob
N69eIdl
"m<eHz]D
public static void main(String[] args) FN8=YUYK%
{ o>QFdx
new TestMethod(); DT1i2!
} Gff[c%I
} ;8 /+wBnm
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