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)); ^Zlbs goZ
} zR?1iV.]
for(int i=0;i<nEndPos.length-1;i++) qipS`:TER
{ 1+Vei<H$
nEndPos = nStartPos[i+1]; MPLeqk$;
} tZ:fOM
nEndPos[nEndPos.length-1] = nFileLength; ACF_;4%&
} .:tR*Kst`7
} "WH &BhQYD
wkT4R\H>
[5Zi\'~UH)
//启动子线程 nWUau:%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; epcvwM/A
for(int i=0;i<nStartPos.length;i++) P#"_H}qC*
{ T7N\b]?j@Y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,QLy}=N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tR_DN
nStartPos,nEndPos,i); o_r{cnu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^$<:~qq!
fileSplitterFetch.start(); }{v0}-~@
} 4 &0MB>m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,,-j5Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M->#WGl\B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f|2QI~R
nEndPos = " + nFileLength); ~O 4@b/!4
// fileSplitterFetch[nPos.length-1].start(); i(xL-&{
zoj w^%W
S(:|S(
//等待子线程结束 Az/P;C=
//int count = 0; k0xm-
//是否结束while循环 @"m+9ZY
boolean breakWhile = false; 9xL`i-7]
2-^['R
w7~&Xxa/
while(!bStop) _HkQv6fXpE
{ F0'8n6zj
write_nPos(); Hq,znRz~`
Utility.sleep(500); ;9qwB
breakWhile = true; !0cb f&^:
xww\L &y
OGW0lnQ/
for(int i=0;i<nStartPos.length;i++) u2*."W\
{ $C8s
if(!fileSplitterFetch.bDownOver) q2M%AvR
{ N]G`]
breakWhile = false; .G|U#%"6x
break; o^u}(wZ{
} 4hUUQ;xj
} Nl{on"il
if(breakWhile) mHNqzdaa
break; ~~#/jULbV
SnoEi~Da
u#0EZ2>#
//count++; H)K.2Q
//if(count>4) oB+@05m8
// siteStop(); ]Yf8
} mQ\oR|
TaZlfe5z
r6kQMFA
System.err.println("文件下载结束！"); N Q}5'
} +sXnC\
catch(Exception e){e.printStackTrace ();} 07Oagq(
} ]jV1/vJ-!
u<HJFGLzI
[LSs|f
//获得文件长度 qtp-w\#S$
public long getFileSize() C(}Kfi@6N
{ dkZ[~hEQG-
int nFileLength = -1; Rtai?
try{ }$:ha>
URL url = new URL(siteInfoBean.getSSiteURL()); EtDzmpJR>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O! w&3 p
httpConnection.setRequestProperty("User-Agent","NetFox"); ?$b*)<
7[8d-Sf24{
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int responseCode=httpConnection.getResponseCode(); 5~"m$/yE
if(responseCode>=400) P2 +^7x?
{ xic&m5j m
processErrorCode(responseCode); #}8gHI-9%
return -2; //-2 represent access is error L(BL_
} AUR{O
5ma~Pjt8}
hy@e(k|S]U
String sHeader; > Cx;h=
_Tf0L<A'R
q_:B=w+bC
for(int i=1;;i++) -J++b2R\%
{ 'zQp64]F
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y>K3.*.
//Utility.log(in.readLine()); ;*e$k7}F
sHeader=httpConnection.getHeaderFieldKey(i); I0sw/,J/Z
if(sHeader!=null) 8FBXdk?A
{ wQX%*GbL2
if(sHeader.equals("Content-Length")) 0f,Ii_k bT
{ <:~'s]`zf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d'p@[1/
break; nAyyjd3!S
} lUHpGr|U%
} E\~!E20^
else tEllkHyef
break; Q_A?p$%;L
} It8@Cp.dU
} <Kq!)) J'
catch(IOException e){e.printStackTrace ();} -)E6{
catch(Exception e){e.printStackTrace ();} +Z/aG k;
$9<P3J 1
y?V#LW[^E
Utility.log(nFileLength); {c=H#- A
&fwb?Vn4
u]t#Vf-$u
return nFileLength; o&rNM5:
} )n$RHt+:>
T28Q(\C:}
WO{9S%ck
//保存下载信息（文件指针位置） E XQ3(:&
private void write_nPos() $-_@MT~
{ Ga$EM
try{ $:*/^)L
output = new DataOutputStream(new FileOutputStream(tmpFile)); *iujJi
output.writeInt(nStartPos.length); ]q@W(\I
for(int i=0;i<nStartPos.length;i++) MJ`BlE,Fmb
{ zY\MzhkX,
// output.writeLong(nPos); | PzXN+DW
output.writeLong(fileSplitterFetch.nStartPos); 6s&%~6J,
output.writeLong(fileSplitterFetch.nEndPos); {i:Ayhq~&
} EN~ha:9
output.close(); |dk9/xdX
} = k>ygD_
catch(IOException e){e.printStackTrace ();} 2(NN QU@Uz
catch(Exception e){e.printStackTrace ();} O`='8'6zW\
} c|~f[
8Sg:HU\
WJw %[_W
//读取保存的下载信息（文件指针位置） *Duxabo?
private void read_nPos() -wn(J5NnR
{ Xq.GvZS`
try{ A*+KlhT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8J+:5b_?
int nCount = input.readInt(); F$>^pw
nStartPos = new long[nCount]; RyN?Sn5)
nEndPos = new long[nCount]; ;NrU|g/ksX
for(int i=0;i<nStartPos.length;i++) l|~SVk|
{ -hpMd/F
nStartPos = input.readLong(); 1$rrfg
nEndPos = input.readLong(); 7Dwf0Re`
} oA$]%
input.close(); I=wA)Bli1p
} DX@*lM
catch(IOException e){e.printStackTrace ();} K7gqF~5x~
catch(Exception e){e.printStackTrace ();} vhu5w#]u*
} :X~{,J
)x&OdFX
&oqzQ+H
private void processErrorCode(int nErrorCode) UNd+MHE74I
{ &io*pmUm6
System.err.println("Error Code : " + nErrorCode); %%Z|6V74
} >PK\bLEo
D*o[a#2_
8i?h{G IMV
//停止文件下载 h**mAa0fo
public void siteStop() FQ6{NMz,h
{ gjhWoZV
bStop = true; dFVm18
for(int i=0;i<nStartPos.length;i++) Z\P&i#
fileSplitterFetch.splitterStop(); 9x[|75}l
rD SUhO{V
PEHaH"|([=
} s9}VnNr
} Fwv(J_'q
//负责部分文件的抓取 Xw[|$#QKM
**FileSplitterFetch.java +b6kU{
*/ '9#h^.
package NetFox; 5$p7y:
NHq*&xy
5qx$=6PT
import java.io.*; [}!obbM
import java.net.*; h>A}vI*:
c<j+"
.jjvS
public class FileSplitterFetch extends Thread { !aub@wH3
qT+:oMrTSm
\Z%V)ZRi=
String sURL; //File URL %["V "{ z
long nStartPos; //File Snippet Start Position "<I*ViZ
long nEndPos; //File Snippet End Position ISl-W1u}
int nThreadID; //Thread's ID 7BDoF!kCx
boolean bDownOver = false; //Downing is over */yR_f
boolean bStop = false; //Stop identical {QRrAi
FileAccessI fileAccessI = null; //File Access interface 8]-c4zK
a)GT\1q
p[M*<==4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A('_.J=
{ O*zF` 9
this.sURL = sURL; fA>FU/r
this.nStartPos = nStart; #'jd.'>
this.nEndPos = nEnd; R-2V C
nThreadID = id; > : ;*3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SH${\BKup
} SvD^'( x
T1Y_Jf*KJ
l&1R`gcW
public void run() nofK(0TF
{ juc;]CHt'
while(nStartPos < nEndPos && !bStop) geB]~/-p
{ Ue22,Pp6
8f0Ytfhw
4?)-;Hx_X
try{ t&99ZdE
URL url = new URL(sURL); &;O)Dw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IrZ!.5%tV
httpConnection.setRequestProperty("User-Agent","NetFox"); P<WCW3!JZ
String sProperty = "bytes="+nStartPos+"-"; *nh.&Mv|
httpConnection.setRequestProperty("RANGE",sProperty); 2gnmk TyF
Utility.log(sProperty); ZhpbbS
Z#P:C":e
R8<'m
InputStream input = httpConnection.getInputStream(); l /\n7:
//logResponseHead(httpConnection); M;Dk$B{;R
EsR$H2"
'6&a8&:
byte[] b = new byte[1024]; 9s}y*Vp
int nRead; BCtm05
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8S_v} NUm
{ L&2 Zn{#`
nStartPos += fileAccessI.write(b,0,nRead); z1u1%FwOfM
//if(nThreadID == 1) n!K<g.tjW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {v>orP?
} D7"RZF\)
YzD6S*wb
{KO+t7'Q
Utility.log("Thread " + nThreadID + " is over!"); PLmf.hD\
bDownOver = true; v!EE[[
//nPos = fileAccessI.write (b,0,nRead); Q7b$j\;I
} &7CAxU;i3
catch(Exception e){e.printStackTrace ();} wUbs9y<
} JM-rz#;1
} (?7=$z!h
gZD,#D.hR
dUg| {l
//打印回应的头信息 zz1e)W/
public void logResponseHead(HttpURLConnection con) ]VU a$$
{ g,N"o72)
for(int i=1;;i++) IfdgMELk
{ MSw:Ay[9
String header=con.getHeaderFieldKey(i); *j0kb"#
if(header!=null) LYv$U;*+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hD5G\TR.
Utility.log(header+" : "+con.getHeaderField(header)); mSu1/?PS
else jK{)gO
break; \:/:S"-
} 3Y}X7-|)Z
} aMaFxEW
*75?%l
(t\ F>A
public void splitterStop() '[nH]N
{ 3:;2Av2(X.
bStop = true; j\Z/R1RcW
} X-&U-S;
|rDv!m
0Q1sJDa.
} </OZ,3J=
dfmxz7V
-8]M ,,?
/* 85Hb~|0
**FileAccess.java lQolE P.pc
*//文件访问(定位，写) x*" 0dYH
package NetFox; LS=HX~5C
import java.io.*; 'L"dM9#>
)fo9Qwe
Y^Olcz
public class FileAccessI implements Serializable{ D/$$"AT
-m.SN>V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f;k'dqlv
RandomAccessFile oSavedFile; >%~%O`+
long nPos; *Hnk,?kPq
FYe(SV(9
k>8,/ AZd
public FileAccessI() throws IOException `n# {}%
{ zMUifMiAj
this("",0); _p~lL<q-K[
} ;&N;6V"}
_;Q1PgT
3\xvy{r
public FileAccessI(String sName,long nPos) throws IOException PV*U4aP
{ nzdJ*C
oSavedFile = new RandomAccessFile(sName,"rw"); St6U
this.nPos = nPos; YuZxKuGy
oSavedFile.seek(nPos); -}B&>w,5
} k8}*b&+{vz
g)<t=+a
Lwg@*:`d
public synchronized int write(byte[] b,int nStart,int nLen) 0koC;(<n
{ uH}cvshv
int n = -1; :CQ-?mT^LA
try{ _dT,%q
oSavedFile.write(b,nStart,nLen); /idQfff
n = nLen; m{/?6h 1
} b|cUKsL5
catch(IOException e) ng-g\&-
{ z]NzLz9VfL
e.printStackTrace (); `|1#Vuk
} |g3a1El
F0O/SI(cA
a|*{BlY
return n; ov{
} uIG,2u,
ZE())W"
wgK:^DP
} 6w d0"
h|_E>6d)
Sc!{ o!9\
/* qjsS2,wM
**SiteInfoBean.java [dK5kO
*/ j0p'_|)(
package NetFox; ] Fx9!S
1]L 0r
C0xjM0
public class SiteInfoBean { X 8V^
t,*hxzD"
jXBAo
private String sSiteURL; //Site's URL r>=)Y32Q
private String sFilePath; //Saved File's Path \;z*j|;B
private String sFileName; //Saved File's Name { XN"L3A
private int nSplitter; //Count of Splited Downloading File [>IAS>
m'))prl
IpX>G]"-C
public SiteInfoBean() ^6*2a(S&
{//nSplitter的缺省值为5 d66 GO];"
//default value of nSplitter is 5 73kF=*m
this("","","",5); <p<J;@
} $"d< F3k
2L#$WuM~^
LRqBP|bjCD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U2=PmS P
{ t;7 tuq
sSiteURL= sURL; v-;j44sB
sFilePath = sPath; p#VA-RSUQ|
sFileName = sName; N|n"JKw)
this.nSplitter = nSpiltter; ,4bqjkX5q
"T`Q,
xwZcO
} H'fmQf
a9CY,+z5B
iRo/~(
public String getSSiteURL() qSRE)C=)
{ wHSas[4k
return sSiteURL; l-Hp^|3Wq
} ggr\nY
PVGvjc
pDGX$1O"
public void setSSiteURL(String value) X>Cl{.
{ B|Y6;4?
sSiteURL = value; (mHCK5
} 481SDG[b
dqU bJc]
?mdgY1
public String getSFilePath() a#iJXI
{ qNI2+<u)j
return sFilePath; ('qu#.'
} (Kl96G<Wej
<r_L-
F;5S2:a@Z
public void setSFilePath(String value) g$c\(isY;
{ YQb43Sh`
sFilePath = value; ;naD`([
} _lrCf
>wiW(Ki}
A %iZ_h^
public String getSFileName() 9%>GOY
{ xEt".K
return sFileName; ={[s)G
} VKcO]_W1
Mqu>#lL
q*,g
public void setSFileName(String value) (Ev/R%Z
{ wAC*D=Qj
sFileName = value; bLrC_
} 2f'3Vjp~G
| |=q"h3(
&tT*GjPwg;
public int getNSplitter() W'l &rm@
{ `Pa)H
return nSplitter; cNi)[2o7
} M_wqb'=
{H FF|Dx
O?<R.W<QI
public void setNSplitter(int nCount) oxN~(H)/ #
{ ['p%$4i$
nSplitter = nCount; "PM!03rb
} !;";L5()
} ;9>(yJI+
biTET|U`$
BU-m\Kf)
/* ^oNk}:>
**Utility.java 0/7y&-/(
*/ zJE$sB.f
package NetFox; Bvke@|]kW
F!FXZht$P
ykY#Y}?^
public class Utility { 0'Kbh$LU
8!a6)Zeux
Q;m:o8Q5
public Utility() #/u%sX`#y
{ &/K:zWk3mx
7X\azL
!&f(Xs
} vYT%e:8)q
Nqih LUv
//线程睡眠 E'|@hL-jn
public static void sleep(int nSecond) CAGaZ rx
{ .G"UM>.}d
try{ GtQ$`~r
Thread.sleep(nSecond); pkd#SY
} JI{|8)S
catch(Exception e) ~*WSH&ip
{ [ugBVnma
e.printStackTrace (); fmuAX w>
} QLx]%E\
} s bf\;_!
*h=|KOS
//日志 >Qk4AMIO
public static void log(String sMsg) K8,fw-S%
{ eK%~`Y
System.err.println(sMsg); }]0f -}
} 9mdp\A
h?f)Bt}ry
3B }Oy$p
public static void log(int sMsg) ,uEi*s>
{ +9S_H(
System.err.println(sMsg); !}u'%
} bERYC|
} ET;=o+\d
gwvy$H
Q+d9D1b
/* pNY+E5
**TestMethod.java yqdhLX|Mk
*/ wYTF:Ou^5~
package NetFox; 7O3\
a78&<
[I*BEJ;W'
public class TestMethod { .Rq|F
/ESmQc:DWB
yFp8 >
public TestMethod() }@-4*5P3
{ ///xx/weblogic60b2_win.exe B(<;]
try{ ekB!d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >P7|-bV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *,w9#?2x
SiteFileFetch fileFetch = new SiteFileFetch(bean); [[{y?-U
fileFetch.start(); tx=~bm"*?
} wO6`Ap t1:
catch(Exception e){e.printStackTrace ();} Etk`>,]Y>y
&%QtUPvr9
BdHLow
} _<?lP$Xr
92}UP=RW!
VH&6Tm1
public static void main(String[] args) V,=V
{ F<wwuCbF
new TestMethod(); &lg+uK
} !C&!Wj
} A;~u"g'z&
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