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)); H<NYm#a"
} 1/&j'B
for(int i=0;i<nEndPos.length-1;i++) Z&.FJZUP
{ *E$D,
nEndPos = nStartPos[i+1]; Zb9@U: \
} }(hE{((o
nEndPos[nEndPos.length-1] = nFileLength; +i)1 jX<
} ^ g4)aaBZ
} Y^6=_^
t: [[5];E
ax3:rl
//启动子线程 Q]|+Y0y}X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zM@iG]?kc
for(int i=0;i<nStartPos.length;i++) 2<988F
{ *50Ykf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B' :ZX-Q)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P{}Oe *9"
nStartPos,nEndPos,i); Pu9.Uwx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T.(SBP
fileSplitterFetch.start(); xE)pj|
} o<g (%ncr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )E4COw+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qlgh$9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Uc6U!X
nEndPos = " + nFileLength); R/b=!<
// fileSplitterFetch[nPos.length-1].start(); 2#E;5UYu
2XXEg>CU
*uv\V@0
//等待子线程结束 d->b9
//int count = 0; UWusSi3+LG
//是否结束while循环 {K|{a
boolean breakWhile = false; p[/n[@<8=
XBr>K>(
z?gJHN<
while(!bStop) HFDg@@
{ ]3I_H+hU
write_nPos(); Jz|(B_U
Utility.sleep(500); xv%}xeEV
breakWhile = true; F_21`Hj
o3W5FHFAv
8bK}&*z<
for(int i=0;i<nStartPos.length;i++) []Fy[G.)H
{ kh5V&%>?
if(!fileSplitterFetch.bDownOver) d")r^7
{ 8WyG49eic
breakWhile = false; ##n\9ipD
break; P,%|(qB
} ZtvU~'Q
} @eMyq1ZU
if(breakWhile) t)m4"p7
break; 8ziYav
a%]p*X!
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//count++; z[k2&=c
//if(count>4) DMf9wB
// siteStop(); P;y/`_jo
} A%2!Hr
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zeua`jQ
System.err.println("文件下载结束！"); y7w>/7q
} ^{Vm,nAQqs
catch(Exception e){e.printStackTrace ();} Zg'[.wov
} 2 43DdIG$
<B fwR$
rcbixOT
//获得文件长度 C4G)anT
public long getFileSize() '*-SvA\Cx
{ L{Th>]X
int nFileLength = -1; 4Cfwz-Qo
try{ zH_q6@4
URL url = new URL(siteInfoBean.getSSiteURL()); JBYQ7SsAS0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dKMuo'H'%
httpConnection.setRequestProperty("User-Agent","NetFox"); _AO0:&
mrbIoN==`
ydFY<Mb(o
int responseCode=httpConnection.getResponseCode(); >:xnjEsi$/
if(responseCode>=400) >2|#b
{ K l4",
processErrorCode(responseCode); "s*{0'jo
return -2; //-2 represent access is error !kIw835U
} QxkfP%_g
:C&?(HJ&r
af_zZf!0
String sHeader; _m&VdIPO
=?2y <B
c]LH.
for(int i=1;;i++) v_ J.M]
{ tb i;X=5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /qCYNwWH9
//Utility.log(in.readLine()); J\%:jg( m
sHeader=httpConnection.getHeaderFieldKey(i); Zb1v
if(sHeader!=null) f"tO*/|`
{ hw7_8pAbh
if(sHeader.equals("Content-Length")) T-@pTJ !K9
{ ;klDt|%3j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .dfTv/n
break; 2ReulL8j
} d}G?iX;c}
} z~BB|-kp1
else w Vof_'F1
break; =MXF`k^}
} *K)v&}uw
} r" D|1
catch(IOException e){e.printStackTrace ();} \xdt|:8
catch(Exception e){e.printStackTrace ();} 3xe8DD
0g+@WK6y
u7;A`
Utility.log(nFileLength); i~.[iZf|
F>M$|Sc2
zPmVECS
return nFileLength; GWW@8GNI
} 4 hj2rK'y
VgdkCdWRm_
]`NbNr]K
//保存下载信息（文件指针位置） *Z]| Z4Q/`
private void write_nPos() GWhZ Mj
{ Z:*U/_G
try{ aw 7f$Fqk
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZBXGuf
output.writeInt(nStartPos.length); kgIWgk%
for(int i=0;i<nStartPos.length;i++) <,GHy/u\
{ vBpg6 fX
// output.writeLong(nPos); EK'&S=]
output.writeLong(fileSplitterFetch.nStartPos); `~RV
output.writeLong(fileSplitterFetch.nEndPos); wx!*fy4hL
} V;6M[ic}
output.close(); d#*5U9\z
} Z^|C~lp;n
catch(IOException e){e.printStackTrace ();} ArEpH"}@
catch(Exception e){e.printStackTrace ();} `8-aHPF-
} 6?lg 6a/eO
^Pf&C0xXv
Fv: %"P^
//读取保存的下载信息（文件指针位置） 4"2/"D0
private void read_nPos() c,qCZ-.Sg
{ )k1,oUx
try{ U&5zs r
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W wE)XE
int nCount = input.readInt(); ]UI+6}r
nStartPos = new long[nCount]; t[maUy_A
nEndPos = new long[nCount]; >R:+ml
for(int i=0;i<nStartPos.length;i++) +wSm6*j7=
{ iF0a
nStartPos = input.readLong(); e.+)0)A-
nEndPos = input.readLong(); <It7s1O
} @}Ixr{t
input.close(); $SXxAS1
} I5A^/=bf&
catch(IOException e){e.printStackTrace ();} 10rGA=x'(
catch(Exception e){e.printStackTrace ();} v;Dcq
} Z:hrrq9
hq*JQb;Y}
:6/OU9f/R
private void processErrorCode(int nErrorCode) #R8l"]fxr?
{ L1xD$wl
System.err.println("Error Code : " + nErrorCode); 5:d2q<x:{
} 5{a( +'
vw]nqS~N
=s]{
//停止文件下载 9vTQ^*bm
public void siteStop() 8_m9CQ6 i
{ Zz-;jkX)
bStop = true; ,OCTm%6e
for(int i=0;i<nStartPos.length;i++) :U q]~e
fileSplitterFetch.splitterStop(); t4*A+"~j
Bg h$P
0q>lW &J
} ;5k|gW
} C6M/$_l&a
//负责部分文件的抓取 `.W;ptZ6
**FileSplitterFetch.java -],?kP
*/ cQ41NX@I
package NetFox; Uq.~3V+u
5r<(Z0
j*u9+.
import java.io.*; 0_ \ g
import java.net.*; h /QP=Zd
:\JbWj_j
N^]>R:Stu
public class FileSplitterFetch extends Thread { 4Jr[8P0/A9
\#jDQ
/&d`c=nH
String sURL; //File URL sri#L+I
long nStartPos; //File Snippet Start Position RM1uYFs<
long nEndPos; //File Snippet End Position CD1=2
int nThreadID; //Thread's ID _0["J:s9
boolean bDownOver = false; //Downing is over /A.i5=k
boolean bStop = false; //Stop identical /&:9VMMj
FileAccessI fileAccessI = null; //File Access interface UMwMXmZNJ
~ p.W*skD
k#5e:VOb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException a.IF%hP0xo
{ }.) 43(>]
this.sURL = sURL; 4_I{Q^f
this.nStartPos = nStart; d`<^+p)oy
this.nEndPos = nEnd; =k=2~ j
nThreadID = id; YiuOu(X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WkySTc
} %`'z^W
)xx/di
|Du13i4].&
public void run() Qsxkw
{ &[Zap6]
while(nStartPos < nEndPos && !bStop) #(+HSZm
{ w00\1'-Kz
F` 5/9?;|
64']F1p0
try{ !TL}~D:J
URL url = new URL(sURL); K('lH-3wS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0,$-)SkT
httpConnection.setRequestProperty("User-Agent","NetFox"); rY?F6'}
String sProperty = "bytes="+nStartPos+"-"; >MWpYp
httpConnection.setRequestProperty("RANGE",sProperty); K_|~3g
Utility.log(sProperty); yLO &(Mb
:@`(}5F4
w1#jVcUQ
InputStream input = httpConnection.getInputStream(); kr`BUW3
//logResponseHead(httpConnection); ';\gR/L
nl9Cdi]o
:KP'xf.
byte[] b = new byte[1024]; B=bI'S8\
int nRead; F2`htM@,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UX'NJ1f
{ -0o6*?[Z
nStartPos += fileAccessI.write(b,0,nRead); 0 ;_wAk
//if(nThreadID == 1) {dA ~#fW<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BH0#Q5
} LL[#b2CKa
EY&C[=
C$td{tM
Utility.log("Thread " + nThreadID + " is over!"); 7;}3{z
bDownOver = true; Y-3[KHD
//nPos = fileAccessI.write (b,0,nRead); -Bo~"q
} hRa(<ZK
catch(Exception e){e.printStackTrace ();} #f3;}1(
} KCh
} Mev-M2A
Rs F3#H
G(OT"+O,
//打印回应的头信息 nN`Z0?
public void logResponseHead(HttpURLConnection con) '<&EPUO
{ -)OkG#J@
for(int i=1;;i++) B.mbKntK)R
{ aDl, K;GL
String header=con.getHeaderFieldKey(i); *Qg5Z
if(header!=null) ZE8/ m")
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &[ u6oAR
Utility.log(header+" : "+con.getHeaderField(header)); X`3vSCn
else B>|U-[A
break; 8gbm"!
} B3>Uba*-)}
} [%84L@:h
=,d* {m~A
N+s?ZE*
public void splitterStop() 8PoHBOxpc
{ 'lN*Ys iDi
bStop = true; ZcTL#OTP
} c2/R]%`)9
EID)o[<
<p^*Ydx
} nGv23R(?G
2z.8rNwT
" _:iK]
/* mS:j$$]u
**FileAccess.java ,_Qe}qFU
*//文件访问(定位，写) XewXTd#x
package NetFox; xxoHH#a
import java.io.*; f OM^V{)T
2E3?0DL",
[W9e>Nsp0
public class FileAccessI implements Serializable{ V5u}C-o
D/S>w(=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M9Nk=s! 3
RandomAccessFile oSavedFile; qIDWl{b<
long nPos; hY.e[+
jSie&V@px
^Y{6;FJ
public FileAccessI() throws IOException xTJSr2f
{ #a(%(k S
this("",0); M<A;IOpR+
} `J>E9p<
'&-5CpDUs
#QTfT&m+G}
public FileAccessI(String sName,long nPos) throws IOException \!UF|mD^tG
{ jr,&=C(
oSavedFile = new RandomAccessFile(sName,"rw"); DJViy
this.nPos = nPos; "ep`
oSavedFile.seek(nPos); ASKAgU"h
} X,WQ'|rC
<JL\?)}n
s-,=e
public synchronized int write(byte[] b,int nStart,int nLen) `Di ^6UK(
{ C#U<k0R
int n = -1; z^gQ\\,4
try{ `1fJ:b/M
oSavedFile.write(b,nStart,nLen); {PODisl>\D
n = nLen; W;Ud<7<;Z
} j-lSFTo
catch(IOException e) Rwc[:6;fn
{ I&TTr7
e.printStackTrace (); JrCf,?L^
} yu`KzIU
gp~yt0AU
v8=?HUDd
return n; {{V;:+62
} });cX$
^))PCn_zb
u}K5/hC
} pqyWv;
aBXYri
;cv.f>Cm
/* zwM"`z
**SiteInfoBean.java T}n N=Q4
*/ 6=ZRn gQ
package NetFox; Q`.'-iq
jo9J%vo
`zdH1p^w
public class SiteInfoBean { 2d-TU_JqX
T@;! yz}Pf
Gw ~{V
private String sSiteURL; //Site's URL Qg'c?[~W@
private String sFilePath; //Saved File's Path |d,F-9iw
private String sFileName; //Saved File's Name ==%`e/~Y
private int nSplitter; //Count of Splited Downloading File .S~@BI(|<
L;/9L[s,
LP.HS'M~u
public SiteInfoBean() Sm$p\ORa
{//nSplitter的缺省值为5 h5L=M^z!>
//default value of nSplitter is 5 O&`U5w
this("","","",5); UWQtvQ f
} ;[(=kOI
+7| [b
]Nnxnp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 't +"k8
{ r5t;'eCea
sSiteURL= sURL; JB&G~7Q85
sFilePath = sPath; y,MPGW_
sFileName = sName; <RhOjZgyZ
this.nSplitter = nSpiltter; F(#haJ$>
EkN_8(w
OENzG~
} /8f>':zUb
KMUK`tbaI
>%-Hj6%
public String getSSiteURL() PeO]lq
{ "yg.hK`
return sSiteURL; *8z"^7?^=
} [/ AIKZM<
I[}75:^Rt
?q\FLb%"7
public void setSSiteURL(String value) %dEB/[
{ 7=}6H3|&
sSiteURL = value; d)N^PJ/
} ZB-QABn
Fj S%n$
,mBZ`X@N
public String getSFilePath() =v.{JV#
{ $j57LY|r
return sFilePath; js~tKUvg
} F"!agc2!
\Ke8W,)ew
yH*hL0mO
public void setSFilePath(String value) ODm&&W#*
{ %B@!
sFilePath = value; @&;(D!_&
} Z+ixRch@-s
v2d<o[[C
?-pi,O~(p
public String getSFileName() BWWq4mdb{
{ zG_p"Z7,
return sFileName; _}D%iJg#
} KE<kj$
.Y;b)]@f
aYqm0HCT
public void setSFileName(String value) :pRF*^eU
{ +#4]o }6G
sFileName = value; tv0Ha A
} T=WNBqKo]
UH[<&v
uKv&7p@|_)
public int getNSplitter() hi!`9k
{ qP7G[%=v
return nSplitter; WJfES2N
} 2UiR~P]%
~/2g)IS
{;*}WPYb
public void setNSplitter(int nCount) ]bm=LA
{ </= CZy5w
nSplitter = nCount; 5y]io Jc9-
} >-M ]:=L
} #b'N}2'p#V
%,/lqcFo
$_sYfU9
/* jo}1u_OJ
**Utility.java -ey)J +?t
*/ TjxA#D)
package NetFox; L1sqU-gt
+Gow5-(
%#u.J
public class Utility { l;OYUq~F
[>f]@>
/prYSRn8
public Utility() Z0$] tS
{ Z0-ytODII
&R,9+c
>)NQH9'1
} eX"''PA
eJHp6)2
//线程睡眠 6g"C#&{@
public static void sleep(int nSecond) >"%ob,c:#
{ f8=]oa]
try{ 6W&_2a7*
Thread.sleep(nSecond); ?1peF47Z
} zPR8f-Uvw
catch(Exception e) JEhm1T
{ ,X68xk.'
e.printStackTrace (); eCWPhB6l
} e`iEy=W
} :lgi>^
Ow@v"L;jF!
//日志 EiWd+v,QJQ
public static void log(String sMsg) $ KB
{ ^ q?1U?4
System.err.println(sMsg); ^/toz).Q
} :HRT 2I
E=AVrv5T
jZd}OC<
public static void log(int sMsg) n*<v]1
{ .po>qb6
System.err.println(sMsg); o_f-GO
} )6-9)pH@)
} [ ny6W9
oh~:,
$ J1f.YE
/* -:<lkq&/
**TestMethod.java [|RjHGf
*/ )K;]y-Us[
package NetFox; };b1ahaG
irKIy
k_ Y~;P@
public class TestMethod { Dz;HAyPj
\S4SI
mrM4RoO
public TestMethod() Qhn;`9+L
{ ///xx/weblogic60b2_win.exe fvqd'2 t
try{ T2=HG Z
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s_[VHPN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); DMn4ll|
SiteFileFetch fileFetch = new SiteFileFetch(bean); $4m*kQ
fileFetch.start(); $SY]fNJQ
} I4t*?
catch(Exception e){e.printStackTrace ();} @MbVWiv
fThgK;Qy'U
n?xTkkr0
} p?# pT}1
nlc.u}#
-tLO.JK<
public static void main(String[] args) c5% 6Y2W0
{ e,gyQjJR
new TestMethod(); QJGKQ2^ n
} .c+9P<VmC}
} QkQ!Ep(
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