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)); 6/9h=-w&
} Musz+<]
for(int i=0;i<nEndPos.length-1;i++) ]u_^~
{ `F>1xMm
nEndPos = nStartPos[i+1]; n ?%3=~9
} #N|)hBz9-
nEndPos[nEndPos.length-1] = nFileLength; JlF0L%Rc
} %<e\s6|P:
} HRx%m1H
BEM+FG
'nNw
//启动子线程 P'D~Y#^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7cn"@h rJ
for(int i=0;i<nStartPos.length;i++) ;<#fZ0(l;
{ hGH{Xp[mW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <?P UF,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^yKP 99(
nStartPos,nEndPos,i); j=)%~@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PZ-|W
fileSplitterFetch.start(); %HuQc^
} _[V.%k
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Uq/(xh,t5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [?BmW{*u.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2I:vie
nEndPos = " + nFileLength); b9(d@2MtK
// fileSplitterFetch[nPos.length-1].start(); Y#c11q Z
E~zLhJTUL'
IPcAE!h6zN
//等待子线程结束 k6~k
//int count = 0; :&`Yz
//是否结束while循环 c3|;'s
boolean breakWhile = false; yov:JnWo
?Z]}G
\1RQ),5 %]
while(!bStop) cW),Y|8
{ !+IxPn
write_nPos(); U<eVLfSij
Utility.sleep(500); Y[;Pl$
breakWhile = true; )%C482GO-
J=TbZL4y}4
)^)VyI`O
for(int i=0;i<nStartPos.length;i++) r{kV*^\E
{ tqrvcnQr^
if(!fileSplitterFetch.bDownOver) T}P|uP
{ /'G'GQrr
breakWhile = false; (@M=W.M#
break; H(]lqvO
} bE^Z;q19
} L5cNCWpo
if(breakWhile) y]?%2ud/=
break; 9L?EhDcDV
<l5{!g
&P!^k0NJR
//count++; ]xf{.z
//if(count>4) oCSf$g8q
// siteStop(); m0F-[k3)
} `S<uh9/
(H+'sf^h
5Zn3s()
System.err.println("文件下载结束！"); ;oC85I
} iTbmD
catch(Exception e){e.printStackTrace ();} ,^|+n()O
} ]-)qL[Q
W1y,.6
>Q+a'bd w
//获得文件长度 ,D3q8?j
public long getFileSize() "S[VtuxPCU
{ "SyyOD )WA
int nFileLength = -1; nH% /
try{ y~1UU3k5
URL url = new URL(siteInfoBean.getSSiteURL()); Ft`#]=IS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pWps-e
httpConnection.setRequestProperty("User-Agent","NetFox"); e7/J:n$
GG;M/}E9
.6$ST Ksr
int responseCode=httpConnection.getResponseCode(); u|8`=
if(responseCode>=400) &)fPz-s
{ X~G"TT$)
processErrorCode(responseCode); x`%;Q@G
return -2; //-2 represent access is error tq@<8?
} LiQs;$V
IwFg1\>
,X\z#B
String sHeader; J;"XRE[%5
MkJL9eG
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for(int i=1;;i++) I U4[}x
{ ":"M/v%F
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sNX$ =<E
//Utility.log(in.readLine()); R,Tw0@{O*
sHeader=httpConnection.getHeaderFieldKey(i); ,3GM'e{hV
if(sHeader!=null) w^`n
{ |}q0G~l
if(sHeader.equals("Content-Length")) d-N<VVcy\
{ ])~*)I~Y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q6%m}R
break; K]kL?-A#'
} W .Hv2r3
} l*'jqR')h^
else `?=AgGg
break; qg.[M*
} 2E2J=Do
} _vU,avw
catch(IOException e){e.printStackTrace ();} ,=oq)Fm]
catch(Exception e){e.printStackTrace ();} z0g]nYN%
5/P?@`/eT
Y60ld7H
Utility.log(nFileLength); 4G_dnf_
92 Pp.Rh
"5dh]-m n
return nFileLength; %iD>^Dp
} *A,=Y/
[(btpWxb^
kmov(V
//保存下载信息（文件指针位置） G0]q(.sOy
private void write_nPos() 8% 1hfj
{ ~01rc
try{ KM0#M'dXy
output = new DataOutputStream(new FileOutputStream(tmpFile)); HNU[W8mg8
output.writeInt(nStartPos.length); c}v:X Slh7
for(int i=0;i<nStartPos.length;i++) S8"X7\d{
{ b55|JWfC`
// output.writeLong(nPos); 6Mk@,\1
output.writeLong(fileSplitterFetch.nStartPos); `$@1NL7>
output.writeLong(fileSplitterFetch.nEndPos); /~ V"v"7E
} rKJ%/7m
output.close(); Uut,cQ". d
} v S%+
catch(IOException e){e.printStackTrace ();} 2N)Ywqvj
catch(Exception e){e.printStackTrace ();} S$JM01
} te:"1:e
;xth#j
5YC(gv3/
//读取保存的下载信息（文件指针位置） $yCj80m\
private void read_nPos() =C#,aoa!
{ 4vBbP;ELWq
try{ mH8s'F
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `fc*/D
int nCount = input.readInt(); 6f1;4Jfp
nStartPos = new long[nCount]; *ZaK+ B
nEndPos = new long[nCount]; Vs07d,@w>
for(int i=0;i<nStartPos.length;i++) PCaa_ 2
{ t1ZZru'r
nStartPos = input.readLong(); bjQfZT(
nEndPos = input.readLong(); 89 fT?tT
} ]L&_R^
input.close(); (V=lK6WQm
} lsio\ $
catch(IOException e){e.printStackTrace ();} hgVwoZ{`]
catch(Exception e){e.printStackTrace ();} UZ](X/
} rSEJ2%iF*
r2sog{R
dOiy[4s
private void processErrorCode(int nErrorCode) ut\9@>*J=Q
{ 1.>sG2*P
System.err.println("Error Code : " + nErrorCode); R [uo:.
} ~Kb(`Px@
xc*ys-Nv
s#qq% @
//停止文件下载 :'!?dszS
public void siteStop() cL1cBWd
{ 7<1Y%|x`
bStop = true; 4]dPhsey
for(int i=0;i<nStartPos.length;i++) m CdkYN#
fileSplitterFetch.splitterStop(); E&K8hY%5
fp>o ^+VB
{H>iL
} B2Orw8F
} {'r*Jb0
//负责部分文件的抓取 ?$s2]}v
**FileSplitterFetch.java ?2=c'%w7
*/ ^OQ_iPPI
package NetFox; /?J_7Lg
;w6\r!O,
u YH{4%
import java.io.*; $x2<D :
import java.net.*; vF([mOZ
0cS.|\ZTA
vMC;5r6*d
public class FileSplitterFetch extends Thread { &=7ur
~O^_J)
m=}kGzIY4
String sURL; //File URL @wa/p`gj5w
long nStartPos; //File Snippet Start Position km|~DkJ\a`
long nEndPos; //File Snippet End Position NKI&n]EO
int nThreadID; //Thread's ID c2F`S1Nu<
boolean bDownOver = false; //Downing is over P)}:lTe
boolean bStop = false; //Stop identical UHCx}LGe
FileAccessI fileAccessI = null; //File Access interface U9k}y
~I^]O \?
6"=e+V@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException % vP{C
{ g@EKJFjl
this.sURL = sURL; z&t6,0q`5
this.nStartPos = nStart; `86b
this.nEndPos = nEnd; TLV)mCZ
nThreadID = id; <]!IC]+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8vP d~te
} Aw|3W ]
'$U"RP^(
<Jvrmm[
public void run() O42An$}
{ RI%l& Hm
while(nStartPos < nEndPos && !bStop) SZ1C38bd,.
{ c9ZoO;
{Rz`)qqE
v~xG*e
try{ Jq; }q63:
URL url = new URL(sURL); /y-P)3_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X:!%"K%}
httpConnection.setRequestProperty("User-Agent","NetFox"); "xO`&a{
String sProperty = "bytes="+nStartPos+"-"; VtmUK$k}I
httpConnection.setRequestProperty("RANGE",sProperty); [ z&y]~
Utility.log(sProperty); }0!\%7-Q
8t7hN?,t
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InputStream input = httpConnection.getInputStream(); =AAH}
//logResponseHead(httpConnection); nv8,O=#s
+,KuYa{lu
+X- k)9
byte[] b = new byte[1024]; ![V<vIy
int nRead; +0a',`yc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p1D-Q7F
{ Ri3m438
nStartPos += fileAccessI.write(b,0,nRead); Z?@07Y[|K
//if(nThreadID == 1) Q^F-8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ilHj%h*z
} hFjW.~B
@Ab<I
v>e4a/
Utility.log("Thread " + nThreadID + " is over!"); +HcH]D;
bDownOver = true; I2/wu(~>
//nPos = fileAccessI.write (b,0,nRead); E7D^6G&i
} R.fRQ>rI
catch(Exception e){e.printStackTrace ();} . =+7H`A
} %8-S>'g'
} CkflEmfe
#&/*ll)
-^Lj~O
//打印回应的头信息 :kUH>O
public void logResponseHead(HttpURLConnection con) <37vWK1+
{ SVpe^iQ]1\
for(int i=1;;i++) !6}Cs3.
{ 9o18VJR
String header=con.getHeaderFieldKey(i); :V"}"{(6
if(header!=null) M6I1`Lpf
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XNl!(2x'pb
Utility.log(header+" : "+con.getHeaderField(header)); !XicX9n
else !hc7i=V?
break; - Z|1@s&
} fXqe7[
} 61KJ( rSX3
}1>a71
WU\):n
public void splitterStop() Y#m0/1-
{ KOxD%bX_
bStop = true; OGVhb>LO1
} T]myhNk
o4J K$%
%DN&K
} zz9.OnZ~
Vy?w,E0^:
BkJcT
/* W)"q9(T?%
**FileAccess.java C&SYmYj^c
*//文件访问(定位，写) HR}c9wy,q\
package NetFox; AsLAm#zq
import java.io.*; |p+VitM7
9X(bByEO
FD6|>G
public class FileAccessI implements Serializable{ sM4wh_lO
9}\T?6?8pX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6lhVwgy3A
RandomAccessFile oSavedFile; [DE8s[i-
long nPos; +:t1PV;l
hb_Ia]b
RWoiV10
public FileAccessI() throws IOException x O)nS _I
{ 7}#vANm
this("",0); 78Gvc~j
} %iGME%oXr
e9:l
$`Ou*
public FileAccessI(String sName,long nPos) throws IOException l^vq'<kI
{ wVPq1? 9
oSavedFile = new RandomAccessFile(sName,"rw"); g7H;d
this.nPos = nPos; #Q{6/{bM&J
oSavedFile.seek(nPos); w_-{$8|
} AV'>
jy*wj7fj1
Gg&jb=
public synchronized int write(byte[] b,int nStart,int nLen) RsY<j& f
{ '5Y8 rv<
int n = -1; -py.YZ
try{ z#\Z|OKU
oSavedFile.write(b,nStart,nLen); S38D cWIw
n = nLen; lH6t d
} 6Ym[^U
catch(IOException e) JvUKfsnu{
{ z XvWo6
e.printStackTrace (); z[';HJ0O;
} @#V{@@3$
X=JSqO6V9
OVd"'|&6_
return n; *=I#VN*_<.
} ~/NA?E-c
zso.?`85
^qDkSoqC"
} 55;xAsG
_zOzHc?Q
/Ly%-py-$
/* ctCfLlK
**SiteInfoBean.java Rub""Ga
*/ v-l):TL+=
package NetFox; DB*IVg
%0]&o, w{
[$V_qFv{
public class SiteInfoBean { I8[G!u71)_
6zDJdE'Es
hVlL"w*1
private String sSiteURL; //Site's URL _W!g'HP-D
private String sFilePath; //Saved File's Path qBpY3]/
private String sFileName; //Saved File's Name We9mkwK7C
private int nSplitter; //Count of Splited Downloading File fEpY3od
ja:%j&:
1{,WY(,c
public SiteInfoBean() Mpj3<vj
{//nSplitter的缺省值为5 ~@-Az([H
//default value of nSplitter is 5 A$ S9 `
this("","","",5); L*5&hPU
} Og,,s{\
U,]z)1#X|
+Q'/c0o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q/Gy&8 K
{ 3*;{C|]S
sSiteURL= sURL; weu'<C
sFilePath = sPath; jf})"fz-*
sFileName = sName; s=6w-'; V
this.nSplitter = nSpiltter; }^QY<Cp|
W=|B3}C?
c#l (~g$D+
} Lb];P"2e+
IUZsLNW
eag$i.^aS
public String getSSiteURL() !WY@)qlf
{ @z2RMEC~
return sSiteURL; +/Z:L$C6
} P_qxw-s
./6L&?*`~;
aMHIOA%Kh
public void setSSiteURL(String value) =}V`O>
{ OaZ~
sSiteURL = value; hslJs^
} W9u(
hwO]{)%
}R J2\CP
public String getSFilePath() GI~;2 `V
{ 7f`jl/
return sFilePath; Ck[Z(=b$$:
} 9@S icqx
oACE:h9U
#<?j784
public void setSFilePath(String value) 7{b|+0W
{ :Z/ig%
sFilePath = value; PvA%c<z
} LN7;Yr
rL%xl,cn<
lID5mg31
public String getSFileName() [szwPNQ_
{ FUHjY
return sFileName; 5[@4($q8
} nGP>M#F
XL"e<P;t
}we"IqLb
public void setSFileName(String value) !867DX3*
{ @@I2bHyvb
sFileName = value; HDC`g
} )kdPAw
b|xz`wUH0$
HL_MuyE
public int getNSplitter() B'=*92i>S
{ M r@M~ -
return nSplitter; K&S~IFy
} u{\`*dNx
S4tdWA
zKI(yC
public void setNSplitter(int nCount) l\(t~Q
{ _o`'b80;
nSplitter = nCount; n,fUoS
} RJg# A`
} 1W-!f%
y[}BFUy
GHoPv-#
/* lk+)-J-lj'
**Utility.java ?C4a,%
*/ 9aXm}
package NetFox; , X|oCD
3"<{YEj8U
O[8Lp?
public class Utility { yJgnw6>r2
^91k@MC
L6',s4
public Utility() 1*=[% d7
{ Q}1PPi,
]zD/W%c
<;acWT?(
} 2Gx&ECa,
6vmkDL8{A8
//线程睡眠 8T1`TGSFC
public static void sleep(int nSecond) L1aN"KGMF
{ t<$yxD/R
try{ 2Ejs{KUj
Thread.sleep(nSecond); fXL$CgXG\x
} 9@^/ON\O
catch(Exception e) kKCkjA:o##
{ y_a~>S
e.printStackTrace (); kWr*+3Xq
} 9m8`4%y=
} kH{axMNc
_:TD{EO$
//日志 BI}>"',
public static void log(String sMsg) 56L>tP
{ f)*}L?
System.err.println(sMsg); *X,vu2(I-=
} B-Fu/n
;;UvK v
lMlXK4-
public static void log(int sMsg) w\85D|u
{ X, J.!:4`
System.err.println(sMsg); JP[BSmhAV
} kkqrlJO|
} .*v8*8OJ&
%(n4`@
c?[A
/* A 8&%G8d
**TestMethod.java r$*k-c9Bf
*/ F[Peil+|`
package NetFox; Fnr*.k
,A_itRHH
G;,2cu K
public class TestMethod { 'e0qdY`
Mc{1Cdj
;g?5V
public TestMethod() ~Fisno
{ ///xx/weblogic60b2_win.exe Ei}B9 &O
try{ jz/@Zg",
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Kf(% aDYq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )M}bc1 _
SiteFileFetch fileFetch = new SiteFileFetch(bean); haB$W 4x
fileFetch.start(); |QXW$
} B<6*Ktc
catch(Exception e){e.printStackTrace ();} KJSN)yn\
I_N"mnn@Nr
lOYwYMi
} dpTap<Noby
I'J=I{p*
9;q@;)'5
public static void main(String[] args) u\>Ed9^
{ 7CNEP2}:R
new TestMethod(); ]%G[<zD,1
} (}bP`[@rX!
} ]`+>{Sx 1
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