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)); '85@U`e.
} xXp$Nm]:
for(int i=0;i<nEndPos.length-1;i++) 35|F?Jx.r
{ -HutEbkjx
nEndPos = nStartPos[i+1]; yhhW4rz
} #+I)<a7\
nEndPos[nEndPos.length-1] = nFileLength; ~<!b}Hv
} 5v<X-8"
} 'mx_]b^O
"^_9t'0
Vj(}'h-c\
//启动子线程 f_y+B]?'M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @62QDlt;
for(int i=0;i<nStartPos.length;i++) *8ykE
{ a7KP_[_(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mMo<C_~w&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Pp.qDkT
nStartPos,nEndPos,i); s wgn( -
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }A)>sQ
fileSplitterFetch.start(); QbA+\
} O{u^&V]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7v\K,P8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OT/*|Pn9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BIyNiol$AJ
nEndPos = " + nFileLength); s"G;rcS}#
// fileSplitterFetch[nPos.length-1].start(); 94Wf ]
,-,BtfE3
aM/sD=}
//等待子线程结束 iF:`rIC
//int count = 0; H]>b<Cs
//是否结束while循环 PgZeDUPP
boolean breakWhile = false; ~{MmUp rS
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QQ*yQ\
while(!bStop) :"BZK5{8
{ eF)vx{s
write_nPos(); R?bF b|5t
Utility.sleep(500); =fy~-FN_
breakWhile = true; aDr46TB`J
%heX06
{p#[.E8
for(int i=0;i<nStartPos.length;i++) QI\&D)
{ pi`sx[T@{Z
if(!fileSplitterFetch.bDownOver) NKae~ 1b
{ ;yh}$)^9
breakWhile = false; w s(9@
break; 7kbeAJ+{
} erG@8CG
} %*4Gx +b
if(breakWhile) n- cEa/g
break; P\#z[TuHKC
mG;Gt=4
Gp6|0:2,L~
//count++; b.Wf*I?
//if(count>4) 6@ `'}
// siteStop(); [p3)C<;ZC
} N[G<&f9
\dpsyc
`a.1Af;L
System.err.println("文件下载结束！"); Y>eypfK"
} 0:<dj:%M
catch(Exception e){e.printStackTrace ();} ?V|t7^+:
} t-#Y6U}b+
==d@0`
G(piq4D
//获得文件长度 {eR,a-D!7
public long getFileSize() v&CKtk!3{
{ !Pmv
int nFileLength = -1; 71GLqn?
try{ ?kvc`7>
URL url = new URL(siteInfoBean.getSSiteURL()); -u6`B-T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T""y)%
httpConnection.setRequestProperty("User-Agent","NetFox"); GdN'G
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XWo=?(iA
int responseCode=httpConnection.getResponseCode(); VU>s{_|{
if(responseCode>=400) ~O{sOl _<4
{ ,^JP0Vc*
processErrorCode(responseCode); VN=S&iBa/
return -2; //-2 represent access is error x Hw$
} VK9I#
gd9ZlHo'Id
w}Q|*!?_
String sHeader; G6X
wzAp`Zs2Dm
N"~P` H![x
for(int i=1;;i++) A/NwM1z[o)
{ H9)$ #r6i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 64s9Dy@%F
//Utility.log(in.readLine()); Gq5)>'D?
sHeader=httpConnection.getHeaderFieldKey(i); |L{<=NNs:D
if(sHeader!=null) &Vi"m!Bf
{ D]+tr%
if(sHeader.equals("Content-Length")) -0| '{
{ wL 5p0Xl
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L4SvE^2+
break; &o/&T{t}
} g<~[k?~J
} &libC>a[
else _:om(gL
break; U[~BW[[@f
} uC G^,BQ
} {m}B=u
catch(IOException e){e.printStackTrace ();} d87pQ3e:&
catch(Exception e){e.printStackTrace ();} >VqMSe_v
xU1dy*-
1p,G8v+B
Utility.log(nFileLength); 'w.:I TJf
hD\C[C,
6X5m1+ Oi^
return nFileLength; "z^Ysvw&~
} ?|^1-5l3
hBLg;"=Em
kYs2AzS{d
//保存下载信息（文件指针位置） pCf-W/v
private void write_nPos() j^ZpBNL
{ I_xJ[ALdm
try{ xPqpNs-,
output = new DataOutputStream(new FileOutputStream(tmpFile)); cZL"e
output.writeInt(nStartPos.length); s4SR6hBO
for(int i=0;i<nStartPos.length;i++) u ` 9Eh;
{ T4Z("
// output.writeLong(nPos); ~;m~)D
output.writeLong(fileSplitterFetch.nStartPos); r3ZY`zf
output.writeLong(fileSplitterFetch.nEndPos); =KT7ZSTV
} : M0LAN
output.close(); C bG"8F|4
} \@OKB<ra
catch(IOException e){e.printStackTrace ();} nC`#Hm.V%
catch(Exception e){e.printStackTrace ();} 6?}8z q[
} ~2A<fL,-
2~h)'n7Mw
zGZe|-
//读取保存的下载信息（文件指针位置） \ox:/-[c\<
private void read_nPos() 1Sz5&jz
{ 3 ;.{ O%bX
try{ %XGX(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >1s:F5u"
int nCount = input.readInt(); ,O a)
nStartPos = new long[nCount]; XNu2G19jb
nEndPos = new long[nCount]; =]W{u`
for(int i=0;i<nStartPos.length;i++) [Z Ea3/
{ #FaR?L![Y
nStartPos = input.readLong(); XfbkK )d
nEndPos = input.readLong(); pJ_Z[}d)c
} Y/Y746I
input.close(); " I`YJEv
} "P<~bw5
catch(IOException e){e.printStackTrace ();} 3)0*hq&83
catch(Exception e){e.printStackTrace ();} f.+e
} NV9=~cx
%q>gwq A
Vg[U4,
private void processErrorCode(int nErrorCode) Bfw>2
{ (:T~*7/"
System.err.println("Error Code : " + nErrorCode); W97Ka}Y
} mg >oB/,'Z
RFA5vCG
bk4%lYJ"
//停止文件下载 #On1Q:d
public void siteStop() M;Vx[s,#,
{ Vi#(x9.
bStop = true; 5QmF0z)wR
for(int i=0;i<nStartPos.length;i++) hDp'=}85@
fileSplitterFetch.splitterStop(); 5&94VQ$d
NmtBn^t
Pi*,&D>{7
} =~aJ]T}(
} $/wr?
//负责部分文件的抓取 ^O892-R
**FileSplitterFetch.java )XO2DY1/&
*/ .Uih|h
package NetFox; /Zv}u
'w9tZO\2
M>I}^Zp!
import java.io.*; ,hOJe=u46
import java.net.*; ]Uxx_1$,
54}s:[O
HmX(=Y
public class FileSplitterFetch extends Thread { +U6! bu>C
OB$A"XGAEV
'Y"q=@Ei9
String sURL; //File URL QT-rb~
long nStartPos; //File Snippet Start Position g?@(+\W
long nEndPos; //File Snippet End Position $V\xN(Ed
int nThreadID; //Thread's ID 8@$QN4^u^
boolean bDownOver = false; //Downing is over Q6vkqu5!=
boolean bStop = false; //Stop identical D%50
FileAccessI fileAccessI = null; //File Access interface s@3!G+ -}
<w,aS;v6jp
((?^B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _wHqfj)
{ 3d,|26I7f
this.sURL = sURL; "HYK~V
this.nStartPos = nStart; %|,j'V$
this.nEndPos = nEnd; Y+G4:
nThreadID = id; 7z+NR&'M$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t~bjDV^`
} LTa9' q0
a{u)~:/G
ZMx<:0ai
public void run() 1P[!B[;c
{ 8Ipyr%l
while(nStartPos < nEndPos && !bStop) !A<?nz Uv
{ (,<?Pg7v:f
)T2Sw z/
e1'_]
try{ W~7q&||;C
URL url = new URL(sURL); Z&}94
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @w|~:>/g
httpConnection.setRequestProperty("User-Agent","NetFox"); (sPZ1Fr\o
String sProperty = "bytes="+nStartPos+"-"; thq(tK7
httpConnection.setRequestProperty("RANGE",sProperty); 2#py>rF(
Utility.log(sProperty); B6ys5eQ
L;v#9^Fq
NVOY,g=3X
InputStream input = httpConnection.getInputStream(); @h$7C<
//logResponseHead(httpConnection); +i K.+B
fM8 :Nt$
p-Q1abl
byte[] b = new byte[1024]; sM-k,0z
int nRead; #%E~IA%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fw-LZ][
{ Ejn19{
nStartPos += fileAccessI.write(b,0,nRead); L%=u&9DmU
//if(nThreadID == 1) DuCq16'0T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :@n e29,}
} O*c+TiTb
okfhd{9
! WQEv_G@
Utility.log("Thread " + nThreadID + " is over!"); v/CXX<^U(
bDownOver = true; jg2>=}
//nPos = fileAccessI.write (b,0,nRead); U${dWxC
} 5)mn
catch(Exception e){e.printStackTrace ();} m:K/)v*
} y5oiH
} O~igwFe
H!7/U_AH
mGoUF$9 k
//打印回应的头信息 XFH7jHnL+U
public void logResponseHead(HttpURLConnection con) QCMt4`%'u
{ Vbz$dpT
for(int i=1;;i++) Xo$(zGb
{ ve'hz{W
String header=con.getHeaderFieldKey(i); +jQW6k#
if(header!=null) -k!UcMWP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Pq !\6s@
Utility.log(header+" : "+con.getHeaderField(header)); i]YH"t8GY
else ofRe4 *\j
break; _PQQ&e)E
} = q;ACW,z
} JrS|Ib)6
j#.Aiy:,
q,kdr)-
public void splitterStop() 9Yd<_B#
{ $M#G;W5c
bStop = true; $xNZ.|al
} ,D;d#fJ
arRbq!mO
REc69Y.k
} !-p5j3A4L
FAo\`x
8)/d8@
/* }cEcoi<v!
**FileAccess.java (jtrQob
*//文件访问(定位，写) H $XO]\
package NetFox; !CY:XQm
import java.io.*; d3<7t
Wv8?G~>
RG0kOw0
public class FileAccessI implements Serializable{ \0). ODA(
}&F|u0@b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Iw~R@,
RandomAccessFile oSavedFile; *%E4,(T
long nPos; r roI
d)1 d0ES
_ VKBzOH
public FileAccessI() throws IOException |6v $!wBi
{ e];lDa#4-Y
this("",0); UQc!"D
} u0zF::
jmPnUn
[;t-XC?[nk
public FileAccessI(String sName,long nPos) throws IOException xy))}c%
{ FUzN}"\1
oSavedFile = new RandomAccessFile(sName,"rw"); R-LMV
this.nPos = nPos; >~:Md
oSavedFile.seek(nPos); 0Un?[O
} `i`+yh>pc#
hz:h>Hwy
& 6'Rc#\P
public synchronized int write(byte[] b,int nStart,int nLen) l0 =[MXM4
{ BX\/Am11
int n = -1; >m]LV}">O
try{ +`,;tz=?
oSavedFile.write(b,nStart,nLen); :aQ.:b(n
n = nLen; )G#mC0?PV
} @@JyCUd
catch(IOException e) VWq]w5oQO
{ d|?Xo\+
e.printStackTrace (); xt_:R~/[
} ;/:Sx/#s
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v5>A1\
return n; w=pr?jt1:
} zD)/QFILy
!iO2yp
?4A/?Z]ub
} mG"xo^1_H
jc!m; U t
<d @9[]
/* 8EI9&L>
**SiteInfoBean.java _%q~K (::
*/ F+"_]
package NetFox; > vdmN]
z',Fa4@z
{`QA.he.
public class SiteInfoBean { 0j_kK
(:aU"5M
tI1OmhNN
private String sSiteURL; //Site's URL NMe{1RM
private String sFilePath; //Saved File's Path ]?pQu'-(
private String sFileName; //Saved File's Name H4s~=iB
private int nSplitter; //Count of Splited Downloading File m8ts!6C
MB!9tju
#l ZK_N|1x
public SiteInfoBean() t%;w<1E
{//nSplitter的缺省值为5 l|=4FIMD
//default value of nSplitter is 5 p}^5ru
this("","","",5); T]\c2U
} #8|LPfA
d{"-iw)t
/M_$4O;*@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6$6QAW0+f
{ VGmvfhf#"
sSiteURL= sURL; PD)"od
sFilePath = sPath; -~mgct5
sFileName = sName; z$e6T&u5B
this.nSplitter = nSpiltter; l-Z( ]
X/yq<_ g
DMM<,1
} DcW?L^Mst
qx t0Jr8
j-":>}oW2.
public String getSSiteURL() }5-w,m{8/
{ _dJ(h6%3
return sSiteURL; !R=@Nr>
} 64<;6*
Y !?'[t
X H-_tvB
public void setSSiteURL(String value) q`VL i
{ gcU*rml
sSiteURL = value; lH}KFFbp
} 7uF|Z(
d9K8[Q5^3
f8Iddm#
public String getSFilePath() zaqX};b
{ p49]{2GXb
return sFilePath; zxbfh/=
} X2z<cJG|d@
']r8q %
=~B"8@B
public void setSFilePath(String value) uu9M}]mDl
{ yD7BZI xW
sFilePath = value; 5E&#Kh(I
} Yc:%2KZ"
n0xGIq
qCV<-o
public String getSFileName() Vw;Z0_C
{ TSlB.pw%v
return sFileName; ={qcDgn~C
} @^P^-B
D 2X_Yv
fw%`[(hK
public void setSFileName(String value) cHs3:F~~
{ .ZpOYhk
sFileName = value; U1[)eD`
} !@xO]Jwv
lW+mH=
N3%X>*'
public int getNSplitter() [#PE'i4
{ "Ms;sdjg}&
return nSplitter; ,_2-Op
} rUiYR]mV
a.Ho>(V/4
#b/qR^2qW
public void setNSplitter(int nCount) (}: s[cs
{ w;z7vN~/O
nSplitter = nCount; i0vm00oT
} #z\ub5um
} G]^[i6PQs
dftBD
[q<'ty
/* ;G[V:.o-
**Utility.java C]`uC^6g
*/ fab'\|Y
package NetFox; @~3--
.tngN<f
'xwCeZcg
public class Utility { }^ rxsx`
y.rN(
nbi7rcT
public Utility() /:{%X(8
{ 6TtB3;5
zM'eqo>!c>
f6Qr0Op
} TT$Ao
Ey6R/M)?:y
//线程睡眠 oMh$:jR$
public static void sleep(int nSecond) =2Y;)wrF
{ >Vuvbo
try{ 9U8M|W|d
Thread.sleep(nSecond); 3EoCEPb#
} *@U{[J
catch(Exception e) &!!*xv-z
{ 1W^hPY
e.printStackTrace (); [$N_YcN?
} @Nu2 :~JO
} \2SbW7"/;P
5!-TLwl`j\
//日志 c_lHj#A(l
public static void log(String sMsg) zWsr|= [
{ Zt=|q$"
System.err.println(sMsg); ua\t5M5
} 3h:j.8Z
m[hL GD'Fi
E$8JrL
public static void log(int sMsg) rfXxg^
{ kfy!T rf
System.err.println(sMsg); 0|3I^b
} dcz?5O_{,
} hI[} -
Fr%#
&|v)
/* TpjiKM
**TestMethod.java tUn>=>cWP
*/ fFQ|dE;cF
package NetFox; q+P@2FL
T j$'B[cv
v.0qE}' |
public class TestMethod { }gp@0ri%5
N0`9/lr|
, X5.|9
public TestMethod() kZ]H[\Fs
{ ///xx/weblogic60b2_win.exe `~1!nfFD
try{ e`*}?N4d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w.qtSW6M+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <_?zln:4.
SiteFileFetch fileFetch = new SiteFileFetch(bean); z8kO)'
fileFetch.start(); m/HT3<F
} pR0[qsQM
catch(Exception e){e.printStackTrace ();} )^(*B6;z5
EF/d7
s%[F,hQRk
} QM$UxWo-
r )|3MUj
D9rQ%|}S
public static void main(String[] args) s!6lZ mPM
{ V&Y`?Edc
new TestMethod(); Ky3mzw|
} -4Qub{Uym
} ChBf:`e
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