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)); />wM#)o2
} "6[a%f#Q
for(int i=0;i<nEndPos.length-1;i++) )<J|kC\r6c
{ j`fQN
nEndPos = nStartPos[i+1]; ;m/h?Y~
} KKrLF?rc
nEndPos[nEndPos.length-1] = nFileLength; Z%h _g-C
} A&HN7C%X
} hDO\Q7
L5+X&
R`IFKmA EJ
//启动子线程 &sFEe<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; li!3bv
for(int i=0;i<nStartPos.length;i++) iD;pXE{2s%
{ 79DzrLu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S5Hb9m&&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kTC'`xv
nStartPos,nEndPos,i); :K:oH}4oh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :htz]
fileSplitterFetch.start(); bOEO2v'cQ
} dC&OjBQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6Kl%|VrJs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \a_75^2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e(e_p#
nEndPos = " + nFileLength); F&tU^(7<
// fileSplitterFetch[nPos.length-1].start(); Dd:TFZo
]lX`[HX7
xz$-_NWW
//等待子线程结束 (-<s[VnXP
//int count = 0; Y/%(4q*'
//是否结束while循环 fX ^hO+f
boolean breakWhile = false; .Yw
\wJ2>Q
iMT[sb
while(!bStop) "aU) [
{ fwkklg^
write_nPos(); =:w]EpH"
Utility.sleep(500); `Z#0kpXk_
breakWhile = true; #9(0.!v
mJ_5Vt=
m;_gNh8Ee
for(int i=0;i<nStartPos.length;i++) \ oY/hT_
{ 6KvoHo
if(!fileSplitterFetch.bDownOver) wjq;9%eXk
{ }@)r\t4m
breakWhile = false; Li'>pQ+
break; P{bRRn4Z
} GiZv0>*x
} Mr0<b?I
if(breakWhile) <W>T!;4!
break; D]?eRO9'
f3>L/9[[<P
y;\m1o2
//count++; 65HP9`5Tm
//if(count>4) |;(95
// siteStop(); Jw4#u5$$Z
} ^vj}
s~z~9#G(6
B~CdY}UTsj
System.err.println("文件下载结束！"); & t.G4
} \80W?9qj
catch(Exception e){e.printStackTrace ();} r_x|2 AoO
} /wR,P
iBM;$0Y
u~C,x3yr
//获得文件长度 xg;o<y KF
public long getFileSize() j`D%Wx_
{ nrF5^eZ#
int nFileLength = -1; kS7`g A
try{ QX`T-)T e
URL url = new URL(siteInfoBean.getSSiteURL()); wv7XhY}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hZ[(Ik]*Zd
httpConnection.setRequestProperty("User-Agent","NetFox"); Ah?,9r=U
S"@/F- 81
>1$vG
int responseCode=httpConnection.getResponseCode(); :Rroz]*
if(responseCode>=400) u_Wftb?9
{ anzt;V.;Y
processErrorCode(responseCode); #Q]^9/;|4n
return -2; //-2 represent access is error NT0im%
} nOCCOTf
XkEJ_;:
joRrsxFU
String sHeader; +%~/~1
q:/3uC7
^[6S]Ft(
for(int i=1;;i++) SWLt5dV
{ ${F4x"x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +F4SU(T
//Utility.log(in.readLine()); q`0wG3
sHeader=httpConnection.getHeaderFieldKey(i); -cONC9=
if(sHeader!=null) BN~gk~t_
{ n/6qc3\5i
if(sHeader.equals("Content-Length")) |>~pA}
{ Yo*.? Mq'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Xl %ax!/
break; ?'IY0^
} Tb[1\
} z[sP/{~z
else k9_c<TSzu
break; Ncr*F^J4
} k0v&U@+-J
} fe4Ki
catch(IOException e){e.printStackTrace ();} TF%MO\!
catch(Exception e){e.printStackTrace ();} ;{Nc9d
V#,jUH|
5hvg]w95;
Utility.log(nFileLength); UOa n
:pCv!g2
=L]GQ=d
return nFileLength; k^#+Wma7
} {g]Mx|5Q
XQPlhpcv
U~GQ JR
//保存下载信息（文件指针位置） )gHfbUYS
private void write_nPos() )?MUUI:
{ 0a}a
try{ @~CXnc0
output = new DataOutputStream(new FileOutputStream(tmpFile)); P;U(2;9 N
output.writeInt(nStartPos.length); )Y &RMYy
for(int i=0;i<nStartPos.length;i++) I /z`)
{ GO]5~4k
// output.writeLong(nPos); 5Ly Wg2
output.writeLong(fileSplitterFetch.nStartPos); v+vM:At4
output.writeLong(fileSplitterFetch.nEndPos); i@L_[d^|j`
} C0}@0c
output.close(); 60#eTo?}o
} >pm`(zLn
catch(IOException e){e.printStackTrace ();} ~zYk,;m
catch(Exception e){e.printStackTrace ();} sW&5Mu-
} xl ]1TB@
61W[
1W'0h$5^"
//读取保存的下载信息（文件指针位置） @h,3"2W{Ev
private void read_nPos() WD>z
{ 80%L!x|
try{ e X{#FgFc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]ne
int nCount = input.readInt(); isU4D
nStartPos = new long[nCount]; (b8ZADI*
nEndPos = new long[nCount]; :pdl2#5H^
for(int i=0;i<nStartPos.length;i++) 85_Qb2<'r
{ (3?W)i
nStartPos = input.readLong(); n.7-$1
nEndPos = input.readLong(); &&ZX<wOM
} rlQ=rNrG&E
input.close(); )Ah7
} 5ENEx
catch(IOException e){e.printStackTrace ();} ~X<?&;6
catch(Exception e){e.printStackTrace ();} FWW*f _L
} d]K$0HY
uH |:gF^
P?hB`5X
private void processErrorCode(int nErrorCode) uQYenCNXS
{ K/0Wp %
System.err.println("Error Code : " + nErrorCode); mRIBE9K+&
} ;;K ~
4+J>/ xiZ
qH(HcsgD
//停止文件下载 dC>(UDC
public void siteStop() ,Bs/.htQj
{ )I"I[jDw
bStop = true; tu's]3RE
for(int i=0;i<nStartPos.length;i++) abw5Gz@Ag
fileSplitterFetch.splitterStop(); T|-llhJ8
)fl+3!tq
PJPKn0,W
} DN;|?oNZ
} ]Q#k"Je
//负责部分文件的抓取 gKP=@v%-
**FileSplitterFetch.java 8GeJ%^0o}
*/ FEdFGT
package NetFox; yRR[M@Y
9v/=o`J#
)|6OPR@(#/
import java.io.*; H.< F6
import java.net.*; @RHG@{x{K
b(\Mi_J
`R*SHy! _
public class FileSplitterFetch extends Thread { "fC>]iA8I
I2WWhsNC
1<Vke$
String sURL; //File URL q1Ad"rm
long nStartPos; //File Snippet Start Position :{9HsF"h0
long nEndPos; //File Snippet End Position z@?WhD
int nThreadID; //Thread's ID *).!
boolean bDownOver = false; //Downing is over P1^O0)
boolean bStop = false; //Stop identical Q<Qd*v&-
FileAccessI fileAccessI = null; //File Access interface _p'u!.a?!
X>%li$9J.
(>uA(#Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *i {e$Zv'
{ e>x+Xj1
this.sURL = sURL; J7HY(7Nx
this.nStartPos = nStart; pV O{7I
this.nEndPos = nEnd; t +|t/1s2
nThreadID = id; s Fx0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F*_+k
} qJE_4/<^!
Sx1|Oq]
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public void run() "m`}J*s"
{ X\kWJQ:
while(nStartPos < nEndPos && !bStop) 2BiFP||
{ ZiPz~G0[^
\Vpv78QF;
$Gcjm~
try{ *z};&UsF{
URL url = new URL(sURL); ]cM8TT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kt |j]:
httpConnection.setRequestProperty("User-Agent","NetFox"); `A#0If
String sProperty = "bytes="+nStartPos+"-"; -2j[;kgt}
httpConnection.setRequestProperty("RANGE",sProperty); s4j]kH
Utility.log(sProperty); ?6UjD5NkX
9&{z?*
Vha,rIi
InputStream input = httpConnection.getInputStream(); )q`.tsR>
//logResponseHead(httpConnection); w3#0kl
jOd+LXPJ
u$FL(m4
byte[] b = new byte[1024]; >7r%k,`
int nRead; #/5eQTBD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1bjz :^
{ CF:L#r
nStartPos += fileAccessI.write(b,0,nRead); _sn<"B%>
//if(nThreadID == 1) jO9!:L>b`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nNeCi
} ,~/WYw<o
_ ^'QHWP
ilyF1=bp
Utility.log("Thread " + nThreadID + " is over!"); ?_r{G7|D
bDownOver = true; G7i0P j
//nPos = fileAccessI.write (b,0,nRead); N)PkE>%X
} 9z`72(
catch(Exception e){e.printStackTrace ();} .<Ays?
} ]L2b|a3
} !MVf(y$
x.$cP
ttls.~DG
//打印回应的头信息 wp83E,
public void logResponseHead(HttpURLConnection con) Bw~jqDZ}|
{ L9oLdWa(C
for(int i=1;;i++) 6&QOC9JW+7
{ Lq2jXy5#n
String header=con.getHeaderFieldKey(i); `q`ah_
if(header!=null) zG{jRth
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i'.D=o
Utility.log(header+" : "+con.getHeaderField(header)); XMz*}B6GQ
else ?XeaoD/
break; !pC`vZG"
} j#u{(W'r
} YkE_7r(1
#^yOW^
4|\
public void splitterStop() x$t2Y<_
{ *3]2vq
bStop = true; Kzz/]
} l-Ha*>gX[j
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`PUxR8y
} s}-j.jzB{
$j8CF3d.6
fP6\Ur
/* =M}tet }
**FileAccess.java It<VjN9
*//文件访问(定位，写) bxzx@sF2l
package NetFox; HAo=t
import java.io.*; 'nq~1 >i
f96`n+>xi
Qv g_|~n
public class FileAccessI implements Serializable{ V7`vLs-
sAPQbTSM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RNQq"c\
RandomAccessFile oSavedFile; :I2,
long nPos; \B:k|Pw6~
We\i0zUU
s:iBl/N}
public FileAccessI() throws IOException c`&g.s@N\
{ R4T@ ]l&W
this("",0); bg/=P>2
} P{BW^kAdH
D?UURURf
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public FileAccessI(String sName,long nPos) throws IOException x^ `IZ{!
{ !* KQ2#e
oSavedFile = new RandomAccessFile(sName,"rw"); Jw#7b[a
this.nPos = nPos; Ujlbcv6+
oSavedFile.seek(nPos); ~H:=p
} Om;aE1sW
N8k=c3|
V#|/\-@
public synchronized int write(byte[] b,int nStart,int nLen) GY.iCub
{ &}0QnO_mj
int n = -1; |@d}O8
try{ =HJ7tele
oSavedFile.write(b,nStart,nLen); x%9Ca)r?}
n = nLen; 7&/1K%x9;
} }s:3_9mE
catch(IOException e) *4LRdLMn
{ O*bzp-6\
e.printStackTrace (); 5`$!s17
} XA(.O|VZ
(:o:_U
b|@zjh;]A7
return n; ZHUW1:qs
} /R?[/`)f&
`rK@> -
hOkn@F.
} bfEH>pQ>#
$7]?P;$
U;*t5l
/* sDR Av%w
**SiteInfoBean.java YJ-<t6
*/ <Rs$d0/
package NetFox; fI2y(p{?
hoM%|,0
3 {hUp81>
public class SiteInfoBean { Fw{68ggk
8SLE*c^8
n*' :,m
private String sSiteURL; //Site's URL u8<[Q]5
private String sFilePath; //Saved File's Path m#G,m
private String sFileName; //Saved File's Name ssS"X@VZ \
private int nSplitter; //Count of Splited Downloading File 08{^Ksg
-;ra(L`
r}sO},i
public SiteInfoBean() ?'|GGtvm
{//nSplitter的缺省值为5 cHR*.
//default value of nSplitter is 5 JiO8EIM
this("","","",5); <;'{Tj-"
} wq,&0P-v
7cWeB5e?O
[i.c;'Wy/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W`c$2KS?DO
{ N 3O!8A_
sSiteURL= sURL; _?y3&4N)
sFilePath = sPath; |Kjfh};-C
sFileName = sName; 8B-mZFXpK
this.nSplitter = nSpiltter; qT #=C'?
ZXkrFA |
- US>].
} H3vnc\d~
2xiE#l-V2
B2*>7 kc_s
public String getSSiteURL() 3Nwix_&S
{ =qoOr~
return sSiteURL; zHg=K /
} 7HY8 F5Brx
w|6?A-
|'JN<?
public void setSSiteURL(String value) b/JjA
{ e6H}L:;
sSiteURL = value; 4p+Veo6B
} i%F2^R@!q/
Csp$_uDi
\,n X/f
public String getSFilePath() EE|c@M^
{ ;$1x_ Cb
return sFilePath; 2A =Y
} X[dH*PV
^!i4d))
-{J0~1'#-
public void setSFilePath(String value) ?~T(Cue>
{ /*BK6hc
sFilePath = value; %Ie,J5g5
} ]q4LNo
ZREy I(_
{Y=k`t,
public String getSFileName() AZ^>osr
{ Anpp`>}N
return sFileName; 6I=xjgwvf
} . XbDb
8.^`~ta
N?#L{Yt
public void setSFileName(String value) Zn40NKYc
{ }.U(Gxu$
sFileName = value; 6(t'B!x
} CS*lk!C
[`E_/95
[McHl1a
public int getNSplitter() H^`J(J+
{ ])bgUH
return nSplitter; } _];yw
} f\=,_AQ
ZAeJTCCk
]9'F<T= $_
public void setNSplitter(int nCount) N+5f.c+S-
{ {R[V
nSplitter = nCount; RhT:]
} =h=-&DSA
} `1Md1e:J
sh0x<_
Q%!xw(
/* 7<(U`9W/q
**Utility.java hH-!3S2'
*/ 59:kL<;S-
package NetFox; dD'KP4Io@
BILZ XMf
y?3u6q++
public class Utility { )k[XO
\>EUa}%xn
UUtSme
public Utility() qzHsqlof
{ 4DP<)KX
q3-cWfU
9^C6ZgNS
} LV0gw"
;[g~h |{6
//线程睡眠 &`>dY /Y
public static void sleep(int nSecond) 'u%_Ab_H
{ yDe*-N\'W
try{ =*6frC~
Thread.sleep(nSecond); JJM!pD\h
} wa&:86~l?
catch(Exception e) EL2z&
{ Po\+zZjo
e.printStackTrace (); B%))HLo'
} (U.VCSn
} ov\%*z2=
673G6Nk
//日志 :'fK`G 6
public static void log(String sMsg) {+kWK;1
{ L+lye Ir'
System.err.println(sMsg); AGVipI #
} aK,\e/Oo
m{lS-DlRg
g&ba]?[A
public static void log(int sMsg) ^Ga_wJP8S
{ TC:t!:
System.err.println(sMsg); 4zBcq<R7
} ;t@^Z_z,CR
} d)$seZB
K #JO#
{cw+kY]m4-
/* eR3MU]zF
**TestMethod.java ,d=Dicaz
*/ b+CvA(*
package NetFox; gKPqU@$*
Zyz)`>cB
iq8Hq)I]
public class TestMethod { *s2 C+@ef
1'k,P;s
=)Goip
public TestMethod() ::/vDUDc
{ ///xx/weblogic60b2_win.exe j{/wG::
try{ =_2(S6~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N$Tzxs
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @Hp=xC9V
SiteFileFetch fileFetch = new SiteFileFetch(bean); +J}h
fileFetch.start(); #so"p<7 R
} %.{xo.`a[
catch(Exception e){e.printStackTrace ();} |l?*' =
k9&pX8#
mT1Q7ta*P
} n{c-3w.uD
|B),N f|a
'1\UFz
public static void main(String[] args) q }9n.
{ G)9`Qn
new TestMethod(); T=pKen/
} 2&F H8
} uv7tbI"r
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