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)); )TyL3Z\>(
} xzMa[D4(
for(int i=0;i<nEndPos.length-1;i++) "C=HBJdYB5
{ *D;B%j^;
nEndPos = nStartPos[i+1]; ^gkyi/z
} 8.jd'yp*J
nEndPos[nEndPos.length-1] = nFileLength; `M4;aN
} GFlsI-*`
} 43:~kCF[s
|fTQ\q]W
vn0XXuquzC
//启动子线程 \s<iM2]Kl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `iIYZ3i
for(int i=0;i<nStartPos.length;i++) v_5DeaMF'
{ YQ37P?u@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =q5A@!D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), LAf!y"A#
nStartPos,nEndPos,i); FNmIXpAn*@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h{<^?=
fileSplitterFetch.start(); K]kL?-A#'
} 3u{[(W}08
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7GK| A{r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $am7 xd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P$]Vb'Fz
nEndPos = " + nFileLength); 348Bu7':
// fileSplitterFetch[nPos.length-1].start(); -zc9=n<5
#|$i H kVY
'`[nt25N
//等待子线程结束 2U|Nkm
//int count = 0; mL6/NSSz
//是否结束while循环 yg\A&0I
boolean breakWhile = false; /B1<N}
~ xf9 ml
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while(!bStop) {b/AOR o
{ msY"Y*4
write_nPos(); OIewG5O
Utility.sleep(500); 3<JZt.|
breakWhile = true; 7)_0jp~2
0^["&K/
RE"}+D
for(int i=0;i<nStartPos.length;i++) qKO\;e*
{ T_Y6AII
if(!fileSplitterFetch.bDownOver) 2s6Vy
{ -BoN}xE4
breakWhile = false; Iv/yIS
break; o~iL aN\+
} P'Y8 t
} Y =`3L
if(breakWhile) Rut6m5>
break; ]L&_R^
uN`ACc)ESi
h{PLyWH
//count++; 4El{2cfA
//if(count>4) "lmiGR*u
// siteStop(); ;[9cj&7C<
} }qlz^s
>T!n* -Zn
~Kb(`Px@
System.err.println("文件下载结束！"); P_ZguNH
} d1E~H]X4
catch(Exception e){e.printStackTrace ();} `L;I/Hp
} r`7`f xe
WHpbQQX
'QW 0K]il
//获得文件长度 R jAeN#,?
public long getFileSize() 5 !NPqka}.
{ ZcdS?Z2k
int nFileLength = -1; OdR
try{ U`8)rtYw
URL url = new URL(siteInfoBean.getSSiteURL()); ^d2g"L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |x kixf4zz
httpConnection.setRequestProperty("User-Agent","NetFox"); pxY5S}@
iySmNI
<N`rcKE%~P
int responseCode=httpConnection.getResponseCode(); BM3)`40[]
if(responseCode>=400) (wA|lK3
{ nwkhGQ
processErrorCode(responseCode); mGY74>/
return -2; //-2 represent access is error (8EZ,V:
} 6"=e+V@
mV4} -
z&t6,0q`5
String sHeader; )0'O!O
"3>#[o
[%h^qJ
for(int i=1;;i++) je{5iIr3/
{ .[_&>@bmrP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); iL\\JuY
//Utility.log(in.readLine()); j1d=$'a "
sHeader=httpConnection.getHeaderFieldKey(i); Lh,<q >t
if(sHeader!=null) +V7p?iEY
{ HL!-4kN <$
if(sHeader.equals("Content-Length")) 97&6iTYA
{ `kz_q/K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '"KK|]vJ
break; 4%]{46YnK
} c,-< 4e
} }Jtaq[y\r
else 6zI?K4o
break; ^wHO!$
} Ri3m438
} 0GG;o[<
catch(IOException e){e.printStackTrace ();} h*KhH>\
catch(Exception e){e.printStackTrace ();} o^NQ]BdH8
u*U?VZ5
Fd91Y
Utility.log(nFileLength); }@#eD
dG|\geD
O4#zsr:"
return nFileLength; 2Hd6
} k+i=0P0mf
yZ P+
nDo|^{!L`
//保存下载信息（文件指针位置） un/R7"
private void write_nPos() Zsuh8t
{ +Rvj]vd}&
try{ IrVeP&KM+
output = new DataOutputStream(new FileOutputStream(tmpFile)); @s[bRp`gd
output.writeInt(nStartPos.length); Rza\n8
for(int i=0;i<nStartPos.length;i++) 61KJ( rSX3
{ Jv?e?U
// output.writeLong(nPos); \\T I4A^#
output.writeLong(fileSplitterFetch.nStartPos); DUtpd|
output.writeLong(fileSplitterFetch.nEndPos); T]myhNk
} X >**M
output.close(); zz9.OnZ~
} 7+fik0F
catch(IOException e){e.printStackTrace ();} W)"q9(T?%
catch(Exception e){e.printStackTrace ();} E=B9FIx~<
} vxm`[s|QC
b 9?w _
8sIGJ|ku
//读取保存的下载信息（文件指针位置） sM4wh_lO
private void read_nPos() H;CGLis
{ [DE8s[i-
try{ 3646.i[D
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jv7zvp
int nCount = input.readInt(); 3HA{18{4uP
nStartPos = new long[nCount]; r`krv-,O$
nEndPos = new long[nCount]; m ;KP
for(int i=0;i<nStartPos.length;i++) 99eS@}RC
{ %_u3Np
nStartPos = input.readLong(); g7H;d
nEndPos = input.readLong(); Oo0$n]*;W
} kz&)a>aA
input.close(); !1l2KW<be
} J3zb_!PPE
catch(IOException e){e.printStackTrace ();} EmH{G
catch(Exception e){e.printStackTrace ();} fT@#S}t
} XI0O^[/n{
o0/03O
4j | vzyc
private void processErrorCode(int nErrorCode) !At_^hSqz
{ ve.4""\a
System.err.println("Error Code : " + nErrorCode); *=I#VN*_<.
} ;?y?s'>t&
^qDkSoqC"
Mz06cw&
//停止文件下载 /Ly%-py-$
public void siteStop() ^GbyAYEp
{ Q`oi=OYB
bStop = true; hcBfau;r
for(int i=0;i<nStartPos.length;i++) !~ZL
fileSplitterFetch.splitterStop(); _ x7Vyy5
1jV^\x0
x,>=X`T
} XGUF9arN
} Sd)D-S
//负责部分文件的抓取 RJWlG'i
**FileSplitterFetch.java *R&g'y^d
*/ !qcR5yk`2
package NetFox; GJW1|Fk
Y,0O&'>
^C'k.pV n~
import java.io.*; ,mRN;|N
import java.net.*; auO^v;s
jf})"fz-*
@^P=jXi<
public class FileSplitterFetch extends Thread { GoFC!nx
J>+Dv?Ni$
C!.6:Aj
String sURL; //File URL 2L,e\]2Z
long nStartPos; //File Snippet Start Position !q/?t XM!
long nEndPos; //File Snippet End Position zX5p'8-
int nThreadID; //Thread's ID ./6L&?*`~;
boolean bDownOver = false; //Downing is over I*24%z9
boolean bStop = false; //Stop identical ?d_Cy\G
FileAccessI fileAccessI = null; //File Access interface nmgW>U0jZh
Xu'u"amt
e%qMrR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v&?Bqj
{ ^&,{
this.sURL = sURL; Z|j8:Ohz
this.nStartPos = nStart; ucMl>G'!gX
this.nEndPos = nEnd; +ivz
nThreadID = id; mG2}JWA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 PL VF
} }XAoMp
6L*y$e"Qc
gz$=\=%>RL
public void run() 1ltoLd\{
{ f[%iRfUFw
while(nStartPos < nEndPos && !bStop) *M8 4Dry`y
{ H!xBFiOH$n
ZLO_5#<
kp0>8rkF
try{ Y@pa+~[{h3
URL url = new URL(sURL); "#p)Z{v"!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S#ven&
httpConnection.setRequestProperty("User-Agent","NetFox"); d$>1 2>>
String sProperty = "bytes="+nStartPos+"-"; [y:6vC
httpConnection.setRequestProperty("RANGE",sProperty); SR\#>Qwx_
Utility.log(sProperty); #_H=pNWe
lk+)-J-lj'
NcPzmW{#;g
InputStream input = httpConnection.getInputStream(); , X|oCD
//logResponseHead(httpConnection); qg'm<[
LtNG<n)_BH
zZA I"\;W
byte[] b = new byte[1024]; z?cRsqf
int nRead; (apAUIE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0tl
{ ?XeRL<n
nStartPos += fileAccessI.write(b,0,nRead); M.t5,NJ
//if(nThreadID == 1) ] e&"CF
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /.}&yRR
} 9@^/ON\O
lv{Qn~\y&
v1;`.PWD
Utility.log("Thread " + nThreadID + " is over!"); 8mMrGf[Q\
bDownOver = true; _:TD{EO$
//nPos = fileAccessI.write (b,0,nRead); 6g<JPc
} ,g/UPK8K=
catch(Exception e){e.printStackTrace ();} AR)&W/S)7,
} R*QL6t
} in%+)`'nH7
jd~r~.y
lZb1kq%9g
//打印回应的头信息 <}B]f1zX
public void logResponseHead(HttpURLConnection con) S6Kaw
{ ,Kdvt@vle
for(int i=1;;i++) Oa*/jZjr
{ R{4O*i8#
String header=con.getHeaderFieldKey(i); _a c_8m
if(header!=null) 2< ^B]N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G;,2cu K
Utility.log(header+" : "+con.getHeaderField(header)); }/M ~
else ah~7T~
break; ;)UZT^f`)K
} d~YDg{H
} `yc.A%5
` R^[s56wp
LkJ3 :3O
public void splitterStop() ^W'\8L
{ e}aD<EG
bStop = true; G!%1<SLi.
} Nnx"b 5I}n
~!Onz wmO
'0w'||#1
} v%B^\S3)
$JcU0tPq0
u9'4q<>&
/* l6)*u[}E
**FileAccess.java U9kt7#@FDK
*//文件访问(定位，写) K2)),_,@5+
package NetFox; Q +qN`
import java.io.*; |1;0q<Ka
#y2="$V
%vyjn&13
public class FileAccessI implements Serializable{ Qp%kX@Z'
oDA1#-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >m%\SuXq
RandomAccessFile oSavedFile; >|H=25N>;
long nPos; O{LWQ"@y
5LXK#+Z
dht1I`i"B
public FileAccessI() throws IOException 7?/ Fr(\
{ Rl<~:,D
this("",0); fE7[Sk
} A*E$_N
f`H}Y!W(
O:#t> ;
public FileAccessI(String sName,long nPos) throws IOException $wC]S4C
{ Ij/c@#q.
oSavedFile = new RandomAccessFile(sName,"rw"); ~99Ta]U
this.nPos = nPos; L}x"U9'C
oSavedFile.seek(nPos); q4lL7@_
} rOH8W
rzY7f: '
e2Ba@e-
public synchronized int write(byte[] b,int nStart,int nLen) M9 _h0
{ T?_$
int n = -1; o^7}H{AE
try{ WWHT;ST
oSavedFile.write(b,nStart,nLen); Pg7W:L7
n = nLen; lOcvRF
} <-X)<k
catch(IOException e) xOPSw|!w
{ e#SNN-hKsJ
e.printStackTrace (); Vg&`f
} ATH0n>)
~@MIG
xw]Zo<F
return n; n"d~UV^Uw
} ,$7LMTVDrE
Z'PL?;&+R
%UY=VE\F
} C5 ^_R
:n{rVn}G
5|wQeosXxI
/* enK4`+.7
**SiteInfoBean.java JKGUg3\~
*/ ,k+jx53XV
package NetFox; &I<R|a
|&h!#Q{7l
"EQ}xj
public class SiteInfoBean { !W{|7Es?.
c[@>#7p`o
BqKD+
private String sSiteURL; //Site's URL j?3J-}XC
private String sFilePath; //Saved File's Path `p*7MZ9-
private String sFileName; //Saved File's Name >0T0K`o
private int nSplitter; //Count of Splited Downloading File E&GUg/d
nS]/=xP{
VBBqoyP h
public SiteInfoBean() JxNjyw
{//nSplitter的缺省值为5 qeH#c=DQ
//default value of nSplitter is 5 pcoJ\&&W
this("","","",5); a}El!7RO0
} m-7^$
rL&585
hRtnO|Z6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DM~Q+C=Yr
{ 12;"K?7{
sSiteURL= sURL; VCkhK9(N
sFilePath = sPath; pG:FDlR~
sFileName = sName; _av%`bb&z9
this.nSplitter = nSpiltter; h&;\
6pxj9@X+
RR*z3i`PP
} ,`S"nq
`61VP-r
w9H%u0V?
public String getSSiteURL() |P>> ^,iUn
{ ib;:*
return sSiteURL; ~KHp~Xs`
} JY_+p9KfyQ
M I/9?B
T1\.~]-msb
public void setSSiteURL(String value) \/S?.P#L~
{ _+.z2} M
sSiteURL = value; \7jcZ~FBX%
} )I$_wB!UV
N}pE{~Y
cQS}pQyYN
public String getSFilePath() `cMa Fc-y/
{ /J wQ5
return sFilePath; L`yS'
} 11%^K=dq
0_,V}
Z\4l+.R`
public void setSFilePath(String value) enDjP
{ (LkGBnXE
sFilePath = value; US@ak4Y6Z
} "Do9gW
DLJu%5F
RVlC8uJ;P
public String getSFileName() !!DHfAV]
{ A ElNf:
return sFileName; [gqV}Y"Md
} KR?-<
83OOM;'
E{(7]Wri
public void setSFileName(String value) ro|dB
{ OiJ1&Fz(
sFileName = value; svHs&v
} AW%^Xt
#e{l:!uS\
,M5zhp$
public int getNSplitter() q: ?6
{ 'HH[[9Q
return nSplitter; xCiY jl$
} .ie\3q)
Bd31> %6
bX=A77
public void setNSplitter(int nCount) m';:):
{ kOs_]
nSplitter = nCount; |z-A;uL<
} sJw#^l
} :BNqr[=b
wS hsu_(i
E&7U |$
/* XSpX6fq
**Utility.java k-*H=km
*/ 4pduzO'I
package NetFox; ,1a6u3f,
&?#V*-;^
oDrfzm|[Y
public class Utility { g-bHf]'
d3St Z~&r!
;S7MP`o@
public Utility() f)Z$,&
{ |p-, B>p!
;1'X_tp
hV)D,oN3
} C-V,3}=*2
kD8$ir'UYG
//线程睡眠 xVfAlN37(
public static void sleep(int nSecond) 5N@k9x
{ W_Z%CBjcT
try{ TMpV.iH
Thread.sleep(nSecond); f(6`5/C
} -r@fLkwg
catch(Exception e) qRZv[T%*Q
{ +C' u!^)
e.printStackTrace (); I}q2)@
} | (JxtQqQg
} MX2]Q
3X=9$xw_
//日志 {E@Fk,
public static void log(String sMsg) m(i84~
{ .!e):&(8
System.err.println(sMsg); Vzn0;
} 'y[74?1
BiT #bg
K!Te*?b
public static void log(int sMsg) Z-z^0QO
{ bA!n;
System.err.println(sMsg); AJ}QS?p8s
} K|,P
} Tsch:r S
ZP~Mgz{f
Iv+JEuIi
/* c<bV3,
**TestMethod.java p!B&&)&db
*/ 1yC_/Va1
package NetFox; >cU#($X$^
-@L7!,j
nsn
public class TestMethod { !xk`oW
E:vgG|??
.j^tFvN~L
public TestMethod() -LzkM"
{ ///xx/weblogic60b2_win.exe #NQpr
try{ JYbsta
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |?v(?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C2}n &{T
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7>.d*?eao\
fileFetch.start(); mxD]`F
} }uP`=T!"8
catch(Exception e){e.printStackTrace ();} PWciD '!
E$SYXe[,
wnUuoX(
} ,5V w^@F
|"}oGL6-
pPL)!=o!
public static void main(String[] args) HQ /D)D
{ 4g4[n7
new TestMethod(); _D+pJ{@W
} >AK9F. _z
} )j,Y(V$P
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