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)); g4oFUyk{
} &:S_ewJK7
for(int i=0;i<nEndPos.length-1;i++) N+"Y@X yg
{ y@nWa\iG
nEndPos = nStartPos[i+1]; |pqLwnOu
} [I4K`>|Z
nEndPos[nEndPos.length-1] = nFileLength; o!aKeM~|Es
} Olj]A]v}
} n&r-
N#bWMZ"
/h0-qW
//启动子线程 ie 2X.#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5w@ ;B
for(int i=0;i<nStartPos.length;i++) v"F.<Q
{ dt',)i8D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &oWWc$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Hm-+1Wx
nStartPos,nEndPos,i); })M$#%(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |n}W^}S5
fileSplitterFetch.start(); --Dw
} c1jHg2xim
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {,]BqFXv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MN$j{+!Q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^;6~=@#*C
nEndPos = " + nFileLength); P9B@2#
// fileSplitterFetch[nPos.length-1].start(); 0u,=OvU
PJAE~|a
f`:e#x
//等待子线程结束 hIXGfvUy
//int count = 0; QTz{ZNi!
//是否结束while循环 #h6(DuViKw
boolean breakWhile = false; ;}A#ws_CD_
.sbU-_ij@U
9(|[okB
while(!bStop) +y6|Nq
{ tmRD$O%:
write_nPos(); ojs&W]r0Z
Utility.sleep(500); q&<#)#+
breakWhile = true; /quf'CV}
:0CR=]WM
R`76Ae`R8
for(int i=0;i<nStartPos.length;i++) d;mQ=k 1
{ Dr6Br<yi
if(!fileSplitterFetch.bDownOver) c~5#)AXMT
{ ?uU0NKZA
breakWhile = false; \S=!la_T@m
break; Pl}}!<!<z
} mIFS/C
} ,^26.p$
if(breakWhile) ,H1J$=X'
break; O.TFV.
]N!SG@X+
7Kk rfJqN
//count++; Kp~k!6x
//if(count>4) D4 {gt\V
// siteStop(); (PsA[>F
} ?9H7Twi+T
**_VNDK+
L]K*Do
System.err.println("文件下载结束！"); iJ?8)}
} yZ0;\Tr*J
catch(Exception e){e.printStackTrace ();} @ RTQJ+ms
} ~1|sf8
C;dA?Es>R
[cXu<vjFM
//获得文件长度 g_0"T}09(
public long getFileSize() l>~:lBO
{ X2M<DeF:
int nFileLength = -1; puZ<cV e/
try{ zesEbR)j
URL url = new URL(siteInfoBean.getSSiteURL()); uqTOEHH7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F|xXMpC.f
httpConnection.setRequestProperty("User-Agent","NetFox"); @h>#cwhU
)6bxP&k
sn5N9=\+T
int responseCode=httpConnection.getResponseCode(); _N/]&|.. !
if(responseCode>=400) Xuh_bW&zF
{ :Jhx4/10
processErrorCode(responseCode); `3pe\s
return -2; //-2 represent access is error j@GMZz<
} W.MJyem
g+ 2SB5 2D
R3?~+y&
String sHeader; Vq9hAD|k
%(6f
oYJ&BPuA'
for(int i=1;;i++) \lKQDct. -
{ ?#04x70
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Rn(|
//Utility.log(in.readLine()); Y1`.
sHeader=httpConnection.getHeaderFieldKey(i); s$H5W`3
if(sHeader!=null) %ef+Z
{ Mh~T.;f.qq
if(sHeader.equals("Content-Length")) }[LK/@h
{ KO)<Zh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `(Q58wR}
break; hZ2PP ^
} 2i,Jnv=sR
} 'kH#QO\(e"
else ik8e
break; `d OjCA_&
} hp,T(D|
} HoRLy*nU
catch(IOException e){e.printStackTrace ();} 2mU}"gf[
catch(Exception e){e.printStackTrace ();} _xUhDu%
]"/ *7NM
(/k,q
Utility.log(nFileLength); (]7@0d88
X\1D[n:
ngm7Vs
return nFileLength; #:s'&.6
} Bj@&c>
tCc}}2bC&
h$ZF[Xbfe
//保存下载信息（文件指针位置） _^P>@ ^
private void write_nPos() 1d\K{ 7i#
{ }}_WZ},h
try{ t8?+yG;
output = new DataOutputStream(new FileOutputStream(tmpFile)); []dRDe;#
output.writeInt(nStartPos.length); ioa 1n=j
for(int i=0;i<nStartPos.length;i++) i w m7M
{ P]6pPS
// output.writeLong(nPos); c$e~O-OVD?
output.writeLong(fileSplitterFetch.nStartPos); f^$\+H"W
output.writeLong(fileSplitterFetch.nEndPos); \s~W;m
} 3J(STIxg
output.close(); zcxG%? Q
} OVj,qL)
catch(IOException e){e.printStackTrace ();} 8De `.!Gg
catch(Exception e){e.printStackTrace ();} o,aI<5"
} F&cA!~
:"QRB#EC%
$mlsFBd
//读取保存的下载信息（文件指针位置） X='4N<
private void read_nPos() 2ZE4^j|
{ DcOu=Y> 1
try{ OcSLRN?t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IloHU6h'
int nCount = input.readInt(); ;nh7Elk
nStartPos = new long[nCount]; !0fK*qIL
nEndPos = new long[nCount]; \[D"W{9l
for(int i=0;i<nStartPos.length;i++) rtzxMCSEU
{ -C8awtbC
nStartPos = input.readLong(); G 8NSBaZe
nEndPos = input.readLong(); l;|1C[V
} 0j_!)B
input.close(); JT_#>',
} P AKh v.7
catch(IOException e){e.printStackTrace ();} O]~p)E
catch(Exception e){e.printStackTrace ();} x`o_&09;CG
} ~z< ? Wh
SnXYq7`t
.0a$E`V=D
private void processErrorCode(int nErrorCode) DH9?~|
{ #vDe/o+=
System.err.println("Error Code : " + nErrorCode); Q7DkhKT
} CX1'B0=\r
'E7|L@X"r
\7/xb{z|
//停止文件下载 DAvAozM
public void siteStop() .d8~]@U!<
{ }RyYzm2
bStop = true; 5,mb]v0k
for(int i=0;i<nStartPos.length;i++) (TY^ kySr
fileSplitterFetch.splitterStop(); zF{z_c#3@
yXEC@#?|
Z>X-ueV
} ?VzST }
} L~0B
//负责部分文件的抓取 t;4{l`dk
**FileSplitterFetch.java `[:f;2(@
*/ leyX: +
package NetFox; $Z;0/\r%
EL+}ab2S
;ga~ae=Fg
import java.io.*; Z+vLEEX*uQ
import java.net.*; C"F(kgL
8<g5.$xyz
#cmj?y()
public class FileSplitterFetch extends Thread { : 0%V:B
( E0be.
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String sURL; //File URL y\@XW*_?
long nStartPos; //File Snippet Start Position 0<P -`|X
long nEndPos; //File Snippet End Position N:d" {k
int nThreadID; //Thread's ID Q}m)Q('Rk
boolean bDownOver = false; //Downing is over 4~Z\tP|Q.
boolean bStop = false; //Stop identical qvab>U`
FileAccessI fileAccessI = null; //File Access interface \ (X~Z
Z-/ E$j
43(+3$VM7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7d9%L}+q
{ Put+<o <
this.sURL = sURL; :Tjo+vw7$H
this.nStartPos = nStart; xl<Cstr
this.nEndPos = nEnd; "4ovMan
nThreadID = id; ^WVr@6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |#MA?oz3T
} q'1rSK
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un..UU4
public void run() W/&cnp\
{ H(""So7L
while(nStartPos < nEndPos && !bStop) .=K@M"5&
{ (A?e}M^}
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u/``*=Y@
try{ hB|LW^@v
URL url = new URL(sURL); m+V'*[O{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O@EpRg1
httpConnection.setRequestProperty("User-Agent","NetFox"); %*Y:Rm'>
String sProperty = "bytes="+nStartPos+"-"; NB>fr#pb
httpConnection.setRequestProperty("RANGE",sProperty); h"q`gj
Utility.log(sProperty); ymzlRs1^Ct
N.3M~0M*
}9@,EEhg
InputStream input = httpConnection.getInputStream(); j4Lf6aUOX
//logResponseHead(httpConnection); y=q\1~]Z
)TV'eq
QDyL0l{C
byte[] b = new byte[1024]; <G#JPt6
int nRead; eyUo67'7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IF@)L>-%
{ Rb\\6BU0
nStartPos += fileAccessI.write(b,0,nRead); (uRAK
//if(nThreadID == 1) {HQ?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4GaF:/
} p+A#t~K
$7lI Dt
Nno*X9>~
Utility.log("Thread " + nThreadID + " is over!"); uZg Kex;c
bDownOver = true; =cg0o_q8
//nPos = fileAccessI.write (b,0,nRead); *R8q)Q
} qM]eK\q 1
catch(Exception e){e.printStackTrace ();} /Wk\6
} 5H>[@_u+:
} l*/I ;a$
n Hy|
{3!v<CY'
//打印回应的头信息 `|Tr"xavf
public void logResponseHead(HttpURLConnection con) k%JwS_F
{ q]<cn2
for(int i=1;;i++) 41,Mt
{ \u2p]K>
String header=con.getHeaderFieldKey(i); aQw?r
if(header!=null) <{7B ^'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t&0pE(MO/
Utility.log(header+" : "+con.getHeaderField(header)); mmEr2\L
else Qnph?t>
break; vA:1z$m
} X8p-VCkV
} De\&r~bTW9
Ll%[}C?~]?
$^}?98m
public void splitterStop() !{"{(h)+@
{ GuNzrKDr
bStop = true; 8 <EE4y
} ~[isR|>
kC0F@'D
)"wWV{k
} -+-@Yq$
^6oz3+
"{j4?3f)
/* $#8dtF
**FileAccess.java .[NB"\<q
*//文件访问(定位，写) mKQ!@$*
package NetFox; > QDmSy*&
import java.io.*; 6Jrh'6o@
V-Oy<
Y6&w0~?!
public class FileAccessI implements Serializable{ oaM $<
-6(C^X%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W{Ine> a'
RandomAccessFile oSavedFile; DHd9yP9-
long nPos; C/\)-^
O2-9Oo@#,
G!uoKiL
public FileAccessI() throws IOException g,r'].Jg
{ #jv~FR`4v^
this("",0); 8:|F'{<<b
} AK} wSXF
I!|_C~I`2
?ep93:j
public FileAccessI(String sName,long nPos) throws IOException >PGW>W$
{ 5O%Q*\(
oSavedFile = new RandomAccessFile(sName,"rw"); NDWpV
this.nPos = nPos; v&;q4b4
oSavedFile.seek(nPos); ,dLh`t<\
} %!mJnc%
]ECzb/
@~qlSU&
public synchronized int write(byte[] b,int nStart,int nLen) u`O xY
{ P=OHiG\z
int n = -1; DKx8<yEky
try{ py6|uGN
oSavedFile.write(b,nStart,nLen); =rMT1
n = nLen; T6*naH
} (i^{\zv
catch(IOException e) xlZ"F
{ gu7mGHn-
e.printStackTrace (); pQKR
} #HfvY}[o
@7e h/|Y,
?suNA
return n; g[!t@K
} w$MFCJ:p&
%O#)=M~
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} oJA%t-&%R
$e)d!m.
J=JYf_=4bc
/* ~Pq1@N>n
**SiteInfoBean.java FctqE/>}I
*/ oi^2Pvauh
package NetFox; 33z)F
^1sX22k
$6kVhE!;
public class SiteInfoBean { $vlq]6V8
PGF=q|j9K
*7u~`
private String sSiteURL; //Site's URL rXPq'k'h#-
private String sFilePath; //Saved File's Path ,u8)g;8s
private String sFileName; //Saved File's Name G1=GzAd$5
private int nSplitter; //Count of Splited Downloading File $T.we+u
"7mYs)=
RB`Emp&T
public SiteInfoBean() GVP"~I~/:
{//nSplitter的缺省值为5 ]r8t^bqe
//default value of nSplitter is 5 pC2ZN
this("","","",5); N}HQvlLkF9
} $w4%JBZr
Cp` [0v~0
Vf9PHHH|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %5Hsd
{ \ 'G%%%;4
sSiteURL= sURL; N3nFE:`u]
sFilePath = sPath; mrX 2w
sFileName = sName; uu@Y]0-
this.nSplitter = nSpiltter; B8;jRY
nk|j(D
/n;Ll](ri
} (L}
rH Et]Xa
FKRO0%M4}Z
public String getSSiteURL() _:DnF
{ ,#:*dl
return sSiteURL; 78zjC6}`
} (hWr!(>C4]
\n$s5i-
5G"LuA
public void setSSiteURL(String value) +RWP;rk
{ HI)MBrj;r
sSiteURL = value; qDHiyg^u
} 03$-U0.;-
(7/fsfsF
3NAU|//J
public String getSFilePath() _ZX"gHx
{ G|MjKe4}
return sFilePath; ]wFKXZeK
} ?@8[1$1a
|W4 \
hqrI%%
public void setSFilePath(String value) C%_^0#8-0
{ +EK(r@eV
sFilePath = value; 5{/CqUIl
} XHU&ix{Od
uTgBnv(Y*
_yk} [x0>
public String getSFileName() M0VC-\W7f
{ HEdOo~/~
return sFileName; hp=TWt~
} =.NZ{G
Au3>=x`
x}o]R
public void setSFileName(String value) l}odW
{ t9T3e
sFileName = value; k.=67L
} a Mp*Ap
q,6 y{RyS
5(e?,B }
public int getNSplitter() G%0G$3W"
{ X{KWBk.1
return nSplitter; ?g9mDe;k
} E)z[@Np
%.^8&4$+
=qPk'n9i8
public void setNSplitter(int nCount) Q-;ltJ
{ N5 ITb0Tv
nSplitter = nCount; DwM4/m
} (}E-+:vFU
} uX_A4ht*
vQf'lEFk
FD>j\
/* s33< }O0
**Utility.java rK&ofc]f$
*/ $jMU|{
package NetFox; eBiP\
EGMj5@>
s!S,;H
public class Utility { $T* ##kyE9
t95hI DtD
clfi)-^{K
public Utility() F jdh&9Zc
{ S~^0 _?
&X0/7)*"v
nsR^TD;
} V"":_`1VW
V# Mw
//线程睡眠 [P#^nyOh(
public static void sleep(int nSecond) yH_L<n
{ N!" ]e*q
try{ /;LteBoY
Thread.sleep(nSecond); _YF~DU
} ,Nl]rmI
catch(Exception e) Q]X0O10
{ 48,Aq*JFw
e.printStackTrace (); SPKen}g
} -f?Rr:#
} Y ON@G5^
mY"DYYR>
//日志 lSP{9L6
public static void log(String sMsg) d5<@WI:wz
{ *UVjN_na5
System.err.println(sMsg); 7O5`&Z'-
} $4.mRS97g
4eb<SNi
JtYc'%OF
public static void log(int sMsg) dIv/.x/V
{ 4f,D3e%T|
System.err.println(sMsg); ]e+IaZ[Wo
} v8g3]MVj3
} pJ7wd~wF*
B.fLgQK0
L^PZ\OC
/* q|m8G
**TestMethod.java 9R.IYnq
*/ t!^FWr&
package NetFox; [;B_ENV
9/C0DDb
e #l/jFJU
public class TestMethod { rN? L8
-F,o@5W>Y
U,/NygB~
public TestMethod() Y+N^_2@+C
{ ///xx/weblogic60b2_win.exe ^5vFF@to
try{ p-V#nPb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D[{p~x^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V M[9!:
SiteFileFetch fileFetch = new SiteFileFetch(bean); K8*QS_*
fileFetch.start(); S8j;oJ2d
} u&l2s&i
catch(Exception e){e.printStackTrace ();} fX G+88:2
M%4o0k]E,s
><iEVrpN
} #I9|>XE1
DoWY*2E
bTC2Ya
public static void main(String[] args) xD#PM |I
{ lD2>`s5
new TestMethod(); @Zd+XWFw
} }4xxge?r
} THQW8 V
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