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)); E``\Jre@
} 0J z|BE3Y
for(int i=0;i<nEndPos.length-1;i++) GOU>j"5}2
{ 5sZqX.XVF
nEndPos = nStartPos[i+1]; vxZ :l
} }}X<e
nEndPos[nEndPos.length-1] = nFileLength; N@x5h8
} W6&mXJ^3L
} /r?EY&9G
A$1Gc>C
WB|N)3-1
//启动子线程 g^)8a;/c
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; oR@1/lV
for(int i=0;i<nStartPos.length;i++) u"5 hlccH
{ aB^`3J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2]'cj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +Ua.\1"6
nStartPos,nEndPos,i); dw YGhhm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6}JW- sA
fileSplitterFetch.start(); f7v|N)
} []<N@a6VA>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DP6>fzsl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); s$ZKd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", shuoEeoo
nEndPos = " + nFileLength); S]g`Ds<
// fileSplitterFetch[nPos.length-1].start(); 8;<3Tyjzu
"NvB@>S
G_v^IM#B=
//等待子线程结束 ojbms>a
//int count = 0; |_u|Td(n
//是否结束while循环 m ?#WQf
boolean breakWhile = false; Jq8:33s
<7*d2
W{X5~w(
while(!bStop) 8dlhL8#
{ 7OdJ&Gzd
write_nPos(); Xmv^O
Utility.sleep(500); "}^}3"/.
breakWhile = true; Z_(P^/
PM8*/4Cu.5
U}c05GiQw
for(int i=0;i<nStartPos.length;i++) Lt2<3DB
{ 3FsX3K,_X
if(!fileSplitterFetch.bDownOver) F-GrQd:O=
{ >o4Ih^VB
breakWhile = false; a"!r]=r
break; /c!@ H(^)
} gxCl=\
} W.7XShwd*2
if(breakWhile) il~A(`+YO
break; Jl-:@[;
,r,$x4*
;dquld+q
//count++; }~!KjFbs
//if(count>4) q{2 +Inf#:
// siteStop(); qt=nN-AC(
} b0aV?A}th
EncJB
[?S-on.
System.err.println("文件下载结束！"); I.{%e;Reg
} eD)@:K
catch(Exception e){e.printStackTrace ();} DgGG*OXY
} EeDK ^W8N
qMmhVUx
tE]Y=x[Ux
//获得文件长度 .*{0[
public long getFileSize() OY,iz
{ |*JMCI@Mz
int nFileLength = -1; GEJy?$9
try{ 5uO.@0
URL url = new URL(siteInfoBean.getSSiteURL()); ]}d.h!`<)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iu'At7
httpConnection.setRequestProperty("User-Agent","NetFox"); >"<<hjKJ
8?G534*r@2
7"p%c`*;
int responseCode=httpConnection.getResponseCode(); w3K>IDWI7
if(responseCode>=400) `FRdo
{ W3]?>sLE*
processErrorCode(responseCode); O=\`q6l
return -2; //-2 represent access is error VY j pl
} [=& tN)_
bxvpj
_)-y&
String sHeader; vhL/L?NB$
g%%j"Cz1
f6JC>Np
for(int i=1;;i++) k'PNfx\K
{ `c/mmS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fB`7f $[
//Utility.log(in.readLine()); F~zrg+VDjL
sHeader=httpConnection.getHeaderFieldKey(i); f#| wb~
if(sHeader!=null) %Z{ 7*jtE
{ z99jW<*0
if(sHeader.equals("Content-Length")) I@l }%L
{ M1_1(LSU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3AcCa>
break; 6+W`:0je
} c|(&6(r
} {7+y56[yu
else +~'ap'k m
break; o`~%}3
} O"m(C[+[
} mecm,xwm
catch(IOException e){e.printStackTrace ();} 5sguv^;C5
catch(Exception e){e.printStackTrace ();} ^u$?& #
6 u}c543
_OvIi~KW+
Utility.log(nFileLength); qTrb)95
1Gh3o}z
TmUN@h
return nFileLength; 1 2J#}|
} "cx#6Bo|
:qrCqFl
m 4V0e~]
//保存下载信息（文件指针位置） VTs ,Ln!,U
private void write_nPos() UCI !>G
{ \@F!h8e4
try{ 9q>rUoK^
output = new DataOutputStream(new FileOutputStream(tmpFile)); @%4tWE
output.writeInt(nStartPos.length); i3U_G^8
for(int i=0;i<nStartPos.length;i++) Ztj~Q9mu
{ Z=[?Tf
// output.writeLong(nPos); xOBzT&
output.writeLong(fileSplitterFetch.nStartPos); TY]-L1$
output.writeLong(fileSplitterFetch.nEndPos); H*vd
} Uq:CM6q\
output.close(); %tT=q^%5
} ?b3({P
catch(IOException e){e.printStackTrace ();} t{o&$s93
catch(Exception e){e.printStackTrace ();} 3B3l)eX
} A v[|G4n
WzdE XcY
hVdPO
//读取保存的下载信息（文件指针位置） yvt :/X
private void read_nPos() Pef$-3aP>E
{ J6J|&Z~UT,
try{ <v[UYvZvY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ZFa<{J<2
int nCount = input.readInt(); -|YDKcL
nStartPos = new long[nCount]; mxkv{;ad
nEndPos = new long[nCount]; -efB8)A
for(int i=0;i<nStartPos.length;i++) N!YjMx)P
{ VZEDBZ x*
nStartPos = input.readLong(); ,B||8W9
nEndPos = input.readLong(); Fv2U@n6'v
} I'a&n}jx
input.close(); O+*<^*YyD
} jb0LMl}/A
catch(IOException e){e.printStackTrace ();} RAi]9`*7
catch(Exception e){e.printStackTrace ();} w5R?9"d@
} bZd)4
:%kJ9zW
&N\4/'wV
private void processErrorCode(int nErrorCode) 6qq{JbK
{ :?J0e4.]
System.err.println("Error Code : " + nErrorCode); ,e!9WKJ B
} {aVL3QU
k!= jO#)Rd
5#hsy;q;[
//停止文件下载 iqTGh*k
public void siteStop() Z!SFJ{
{ i5G"@4(
bStop = true; lMRy6fzI
for(int i=0;i<nStartPos.length;i++) #F25,:hY
fileSplitterFetch.splitterStop(); y)#=8oci
aW@J]slg
+-OnO7f
} Nx^r&pr
} E;)7#3gY1
//负责部分文件的抓取 5.X`[/]<r
**FileSplitterFetch.java 4Up\_
*/ 0VwmV_6'<W
package NetFox; ;1Zz-@
8*m=U@5]
-9@/S$i
import java.io.*; &HIG776
import java.net.*; Y.}8lh eH
=VPJ m\*V
V/CZcMY_
public class FileSplitterFetch extends Thread { }`*DMI;-
Q~S3d
0DgEOW9H
String sURL; //File URL fqQ(EVpQ
long nStartPos; //File Snippet Start Position qGH\3g-
long nEndPos; //File Snippet End Position Q]"u?Q]
int nThreadID; //Thread's ID "j] r
boolean bDownOver = false; //Downing is over /%9CR'%*c
boolean bStop = false; //Stop identical =!Ce#p?h,
FileAccessI fileAccessI = null; //File Access interface jo^+
W^Z#_{
YKWtsy
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6p1)wf.J
{ ]5`Y^hS_g
this.sURL = sURL; fx`oe
this.nStartPos = nStart; f )K(la^'
this.nEndPos = nEnd; :HTV8;yc
nThreadID = id; oNK-^N?-T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O~=|6#c
} UYW{AG2C
[H&Z /.{F
>+8Kl`2sw;
public void run() DgB]y6~KXl
{ Rd^X.
while(nStartPos < nEndPos && !bStop) >;M?f!
{ 3Sclr/t
2\, h "W(
#:st>V_h
try{ D^jyG6Ch
URL url = new URL(sURL); byB ESyV!O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZuIw4u(9
httpConnection.setRequestProperty("User-Agent","NetFox"); R;2q=%
String sProperty = "bytes="+nStartPos+"-"; /ig'p53jL
httpConnection.setRequestProperty("RANGE",sProperty); 1j":j%9M
Utility.log(sProperty); +kN/-UsB
QYj8c]8f
->29Tns
InputStream input = httpConnection.getInputStream(); sn6:\X<[
//logResponseHead(httpConnection); oM4Q_An
>L{s[pLJ
o6LZ05Z-&
byte[] b = new byte[1024]; 8R;A5o,
int nRead; Mu?hB{o1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t3b64J[A{
{ UI}df<Ge
nStartPos += fileAccessI.write(b,0,nRead); Z+?V10$
//if(nThreadID == 1) _J+p[=[L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >nA6w$
} S85}&\m&4
dD{{G:V
]BiLLDz(
Utility.log("Thread " + nThreadID + " is over!"); map#4\
bDownOver = true; ck"lX[d1
//nPos = fileAccessI.write (b,0,nRead); WUnmUW[/
} f#3U,n8:
catch(Exception e){e.printStackTrace ();} aHzS>
} R]y[n;aGC
} ds9L4zfO
alB[/.1
` e~nn
//打印回应的头信息 4gRt^T-?
public void logResponseHead(HttpURLConnection con) @=kDaPme92
{ },@1i<Bb
for(int i=1;;i++) 5C^oqUZ
{ zLB7'7oP
String header=con.getHeaderFieldKey(i); sMhUVc4
if(header!=null) b9(_bsc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Aa#WhF
Utility.log(header+" : "+con.getHeaderField(header)); ;Fi(zl
else !gm;g}]szG
break; >PD*)Uq&
} yS)73s/MrY
} ]*M-8_D
">LX>uYmX-
1aQR9zg%
public void splitterStop() ![OKmy
{ 7Y>17=|
bStop = true; GVaIZh<
} S3oSc<&2
(4WAoye|
3TDjWW;#~
} t|ih{0
D$wl.r
$&!i3#FF
/* :XP/`%:
**FileAccess.java M-Tjp'=*
*//文件访问(定位，写) kkz{;OW
package NetFox; [-$:XOO
import java.io.*; {+&qC\YF
('u\rc2R
!Xzne_V<
public class FileAccessI implements Serializable{ 2zz7/]?Q
e[(XR_EY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mEUdJvSG(
RandomAccessFile oSavedFile; 0L5n<<7
long nPos; os3jpFeG'
jBO/1h=
rv\yS:2
public FileAccessI() throws IOException P!apAr
{ wePhH*nQ>
this("",0); *h `P+_Q7
} 88GS Bg:YH
z!<X{& e
0"vI6Lm
public FileAccessI(String sName,long nPos) throws IOException %}nNwuJ
{ A=(<g";m
oSavedFile = new RandomAccessFile(sName,"rw"); VT;Vm3\
this.nPos = nPos; d*e0/#s
oSavedFile.seek(nPos); d\_$Nb*
} z~S(OM@olJ
b85r=tm
zB?} {@
public synchronized int write(byte[] b,int nStart,int nLen) p:GB"e9>H
{ b3Uw"{p
int n = -1; fXV+aZ
try{ 41S.&-u
oSavedFile.write(b,nStart,nLen); <h*r
n = nLen; xDU{I0M
} 4NY}=e5
catch(IOException e) >+P5Zm(_
{ jOYa}jm?
e.printStackTrace (); <;R}dlBASW
} ]f3eiHg*
j!It1B
'F)93SwU
return n; h "MiD
} =Z3{6y}3p
[T(XwA)
7H+IW4Ma
} 8K]5fkC|
=nQgS.D
'nrXRDb
/* gB;5&;T:
**SiteInfoBean.java #%;QcDXRe
*/ 5 +Ei!E89
package NetFox; us,!U
*u i!|;
v*.[O/,EBR
public class SiteInfoBean { JjXuy7XQ
3u)NkS=
rY~!hZ
private String sSiteURL; //Site's URL 8R) 0|v&;
private String sFilePath; //Saved File's Path a+U^mPe
private String sFileName; //Saved File's Name Tke3X\|
private int nSplitter; //Count of Splited Downloading File ~6)A/]6
Mx3MNX/
7O=N78M
public SiteInfoBean() bp>-{Nv
{//nSplitter的缺省值为5 &^v5 x"
//default value of nSplitter is 5 pn:) Rq0
this("","","",5); X{ZcJ8K
} Z8X=Md8=
;V=Y#|o
bc?\lD$$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {Tps3{|wt
{ J|uxn<E<>
sSiteURL= sURL; d3m!34ml
sFilePath = sPath; '@ $L}C#OI
sFileName = sName; o*[n[\cR
this.nSplitter = nSpiltter; kK0.j)(
Q|DVB
e={X{5z0
} xzZ2?zWi
Tuk:: .jD
qy9RYIfZ
public String getSSiteURL() rwJCVkF
{ lR[]A
return sSiteURL; K~C6dy
} EO_:C9=d{
-KuC31s_W
uuD|%-Ng
public void setSSiteURL(String value) DFk0"+Ky
{ m=qEQy6#2u
sSiteURL = value; ho'Ihep,L
} L<}0}y
^Uj\s/
rT&rv^>f
public String getSFilePath() 0Z m^6T
{ gXNlnh%?S
return sFilePath; \W,,@-
} bPlqS+ai_
!nBE[&
i-<1M|f
public void setSFilePath(String value) oc^j<!Rh
{ 'P:u/Sq?m
sFilePath = value; i7%v2_
} B2R^oL'}
1(q&(p
pL& Zcpx
public String getSFileName() f"{|c@%
{ dbE]&w`?d
return sFileName; V,*<E&+
} 4kNiS^h
sa7F-XM
2`[iTBZ=^
public void setSFileName(String value) L&I8lG
{ xA&RMu&
sFileName = value; #80[q3
} -lb,0
7xhBdi[ dQ
,Vc>'4E-
public int getNSplitter() I<``d Ne9Q
{ 9tMaOm
return nSplitter; ^%qe&Pe2
} =(3Yj[>st
PXx:JZsju
&(Yv&jX
public void setNSplitter(int nCount) SyB2A\A
{ Fad.!%[
nSplitter = nCount; mRNA,*
} mr6~8I
} EZY <k#
P,eP>55'K
4eRV?tE9
/* 2m*g,J?ql
**Utility.java (\I9eBm
*/ pef)c,U$
package NetFox; _<8~CWo:
<73dXTZ0
\C&[BQ\
public class Utility { OpNxd]"T
DO^J=e
GBvgVX<
public Utility() ROWI.|
{ _=\J:r|Y:
DH>>u
)@Vz,f\}
} k$ORVU
z{q|HO
//线程睡眠 >x3$Ld
public static void sleep(int nSecond) Od,P,t9
{ *B3 4
try{ `q$a p$?
Thread.sleep(nSecond); n|M~C\*
} Sc/\g
catch(Exception e) D^30R*gV
{ O u-/dE%
e.printStackTrace (); yU{Q`6u T
} <NYf!bx
} 0DB8[#i%:
(>R
//日志 h3`\L4b
public static void log(String sMsg) =>LQW;Sjz
{ 6SqS\ 8
System.err.println(sMsg); ,8`CsY^1
} ;S5J"1)O~
MV?#g-5
SqosJ}K
public static void log(int sMsg) %S$+3q%F
{ I)AbH<G{
System.err.println(sMsg); *I6W6y;E=
} ?nCo?A
} LZI[5tA"
q(9S4F
csd~)a nb
/* b$JrLZs$_
**TestMethod.java _Oc(K "v
*/ WcOnv'l,
package NetFox; WZQ EBXs
6g-Q
{y%cTuC=
public class TestMethod { '5r\o8RjN
^B!cL~S*I
)#Le"&D
public TestMethod() 8-&c%h 1
{ ///xx/weblogic60b2_win.exe hqW),^\>'
try{ N!~5S`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W'Y?X]xr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1$#1
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8n"L4jb(:
fileFetch.start(); {bP )Fon
} [lz#+~rOS
catch(Exception e){e.printStackTrace ();} L:_GpZ_
)jPIBzMys
: =f!>_r+
} i1 >oRT{Z
m|]:oT`M
Ju@8_ ?8=
public static void main(String[] args) A:4?Jd>
{ xS+!/pBf"Y
new TestMethod(); 9q]n&5
} k4-S:kVo
} ;W?mQUo:P8
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