http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); )<%CI#s#
} ^-LnO%h?
for(int i=0;i<nEndPos.length-1;i++) n&!q9CR`
{ ~Ede5Vg!!2
nEndPos = nStartPos[i+1]; #@' B\!<@=
} JXjH}C
nEndPos[nEndPos.length-1] = nFileLength; ^RE[5h6^q
} L&KL]n
} O=eU38n:5u
Kum" }ux
^M1jv(
//启动子线程 Uw]o9 e0S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }vU^gPH
for(int i=0;i<nStartPos.length;i++) 7~r_nP_
{ <Mndr8 H
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ay =B<|!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L#?mPF
nStartPos,nEndPos,i); L=<$^m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9K;g\? 3
fileSplitterFetch.start(); Ng1bjq}E2
} TS`m&N{i")
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6"[J[7up
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g[' 7$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", La28%10
nEndPos = " + nFileLength); HWIn.ij
// fileSplitterFetch[nPos.length-1].start(); \T[OF8yhW
O6vHo3k
DJ0jtv6nQ-
//等待子线程结束 )gz]F_
//int count = 0; _R^ZXtypd
//是否结束while循环 aeVd.`lxM
boolean breakWhile = false; }~Do0XUH
_>a`dp.19
yRi5t{!V
while(!bStop) mo9(2@~<
{ @HTs.4
write_nPos(); /eT9W[a
Utility.sleep(500); ]heVR&bQ
breakWhile = true; xi=0kO
vT MCZ+^g
qo}yEl1
for(int i=0;i<nStartPos.length;i++) S(Z\h_m(
{ WL|71?@C
if(!fileSplitterFetch.bDownOver) :`K2?;DC8
{ NiEz3ODSi
breakWhile = false; Xq_hC"s
break; 2s=zT5
} ~;-2eKw
} 0eKLp8;Lh
if(breakWhile) @NiLKcL#
break; \Unawv~
{3SK|J`
Q,:h`%V
//count++; +vH#xc\'
//if(count>4) R%~~'/2V
// siteStop(); #V)l>
} j+>[~c;0)
-tx%#(?wH
c(29JZ
System.err.println("文件下载结束！"); Zx`/88!x[
} ~.6% %1?
catch(Exception e){e.printStackTrace ();} c}!`tBTm
} g6xQQ,q=l
4=%,0.yt
m<LzgX
//获得文件长度 `gF]
public long getFileSize() C^LxJG{L5
{ 4]E1x l
int nFileLength = -1; _j4K
try{ R6`mmJ+'
URL url = new URL(siteInfoBean.getSSiteURL()); 9':Hh'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S|;}]6p
httpConnection.setRequestProperty("User-Agent","NetFox"); Q);}1'c
t|9vb
\II^&xSF
int responseCode=httpConnection.getResponseCode(); NGRXNh+
if(responseCode>=400) ~[kI![
{ d|`8\fq
processErrorCode(responseCode); <Fv7JPN%
return -2; //-2 represent access is error cp"{W-Q{$
} *3h_'3yo@
VZe'6?#
DZ $O%
String sHeader; kyZZ0
|MN2v[y
qG2P?DR
for(int i=1;;i++) e|>@ >F]K
{ QxuU3#l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \F\xZ.r
//Utility.log(in.readLine()); RH$l?j6
sHeader=httpConnection.getHeaderFieldKey(i); R&:Qy7"
if(sHeader!=null) &|h9L'mr
{ z_#HJ}R=
if(sHeader.equals("Content-Length")) X{[$4\di{
{ ug'^$geM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E(z|LS*3
break; kpy)kS
} /!.]Y8yEH
} GO*D4<#u
else In;P33'p
break; i5_l//]
} O;&5> W,Z
} I.>8p]X
catch(IOException e){e.printStackTrace ();} X)=m4\R
catch(Exception e){e.printStackTrace ();} pcQkJF
jwuSne
{9) HB:
Utility.log(nFileLength); {%RwZ'
ooCfr?E
vv&< 7[
return nFileLength; OLIMgc(W
} 842v^ 2
lusUmFm'*
)C"ixZ>2xQ
//保存下载信息（文件指针位置） OIj.K@Kr
private void write_nPos() 0R? @JC
{ h!uyTgq
try{ Y=|p}>.}
output = new DataOutputStream(new FileOutputStream(tmpFile)); %\HE1d5;
output.writeInt(nStartPos.length); U"/T`f'H z
for(int i=0;i<nStartPos.length;i++) ^[.}DNR95(
{ Q>Klkd5(
// output.writeLong(nPos); .`~?w+ ~
output.writeLong(fileSplitterFetch.nStartPos); tl /i
output.writeLong(fileSplitterFetch.nEndPos); Odwf7>
} 9QX!HQ|5y8
output.close(); 'k]~Q{K$
} eYP^.U)
catch(IOException e){e.printStackTrace ();} 3O;H&
catch(Exception e){e.printStackTrace ();} 1K#[Ef4
} OqS!y( (
im9w|P5
"P?O1
//读取保存的下载信息（文件指针位置） 1#cTk
private void read_nPos() i`e[Vwe2x@
{ ROn@tW
try{ UapU:>!"`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); VqvjOeCbH
int nCount = input.readInt(); } r(b:}DN
nStartPos = new long[nCount]; ;^bfLSWm{
nEndPos = new long[nCount]; [KgO:},c
for(int i=0;i<nStartPos.length;i++) Z[w}PN,xV
{ d)V8FX,t
nStartPos = input.readLong(); uWKmINjv'
nEndPos = input.readLong(); ;<m*ASM.3
} i$%Bo/Y
input.close(); f8[O]MrO;
} ;G}
catch(IOException e){e.printStackTrace ();} ,x1OQ jtY
catch(Exception e){e.printStackTrace ();} @@^iN~uf
} .xwskzJ3
pTi7Xy!Cw
9tv,,I;iU
private void processErrorCode(int nErrorCode) OnE%D|Tq=
{ q++\<\2
System.err.println("Error Code : " + nErrorCode); n_; s2,2r
} $.C-_L
>U`G3(#7S
aL[6}U0(}
//停止文件下载 pl3ap(/
public void siteStop() Lu6g`O:['
{ B(1-u!pz
bStop = true; O6/ vFEB
for(int i=0;i<nStartPos.length;i++) q\?p' i
fileSplitterFetch.splitterStop(); `XH0S`B
Z" ;q w
G3:!]}
} ;AJQ2
} 8Yk*$RR9
//负责部分文件的抓取 U!-Nx9
**FileSplitterFetch.java nS3Aadm
*/ d/yF}%0QI
package NetFox; NjZ~b/
MhCU; !
9MfU{4:;I
import java.io.*; yIn$ApSGY
import java.net.*; 2<B'PR-??y
C`t@tgT
OS; T;
public class FileSplitterFetch extends Thread { @:Zk,
P~{8L.w!>W
}NyQ<,+mq&
String sURL; //File URL u$^tRz9
long nStartPos; //File Snippet Start Position WN=0s
long nEndPos; //File Snippet End Position 0D2I)E72o
int nThreadID; //Thread's ID p&RC#wYu
boolean bDownOver = false; //Downing is over 04dz?`HuB
boolean bStop = false; //Stop identical +={K -g7U
FileAccessI fileAccessI = null; //File Access interface CR'%=N04^
HdxP:s.T
BZ:tVfg.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 131(0nl)=I
{ xrvM}Il
this.sURL = sURL; B2j1GJEO
this.nStartPos = nStart; -c]AS[(
this.nEndPos = nEnd; ciODTq?
nThreadID = id; 3E*m.jX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Sp X;nH-D
} sq`Xz8u
AcuF0KWw/
tjFX(;^[
public void run() V>T?'GbS
{ ~C%I'z'
while(nStartPos < nEndPos && !bStop) nI]EfHU
{ :1UMA@HP
L>~Tc
#}y8hzS$
try{ JXJ+lZmsz
URL url = new URL(sURL); u|t l@_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8-x-?7
httpConnection.setRequestProperty("User-Agent","NetFox"); L_Gw:"-+Q
String sProperty = "bytes="+nStartPos+"-"; '+_>PBOc
httpConnection.setRequestProperty("RANGE",sProperty); [-$ Do
Utility.log(sProperty); t([}a~1}
.c-a$39
dW4jkjap
InputStream input = httpConnection.getInputStream(); oV:oc,
//logResponseHead(httpConnection); iv$YUM+
ffmtTJFC5
&t9V
byte[] b = new byte[1024]; W#<1504ip
int nRead; HGGq;Nbm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :/|"db&`
{ Ldjz-
nStartPos += fileAccessI.write(b,0,nRead); S/5QK(XLC)
//if(nThreadID == 1) 0h@FHw2d
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *[]E5U
} X-HE9PT.
k B>F(^
AChz}N$C
Utility.log("Thread " + nThreadID + " is over!"); |2q3spd
bDownOver = true; A0)^I:&
//nPos = fileAccessI.write (b,0,nRead); f zo'9
} h) Wp
catch(Exception e){e.printStackTrace ();} 12n:)yQy
} &Pr\n&9A
} Zigv;}#
[HQ)4xG
*z0d~j*W;
//打印回应的头信息 Lg7A[\c ~
public void logResponseHead(HttpURLConnection con) EhHxB fAQ
{ w2nReBz
for(int i=1;;i++) \2s`mCY
{ [Iks8ZWr_
String header=con.getHeaderFieldKey(i); "OjAhKfG
if(header!=null) *XTd9E^tXq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X@`a_XAfd
Utility.log(header+" : "+con.getHeaderField(header)); (P)G|2=
else Q|AZv>'!
break; 27eG8
} W r/-{Wt
} lv 8EfN
_HUbE /
C[^V\?3ly:
public void splitterStop() /IpCo
{ #Lhv=0op
bStop = true; G|g^yaq>
} nQc#AFg
@yuiNj.T
bT.q@oU
} gN=.}$Kfu
G>V6{g2Q
n"EKVw7Y
/* aZA``#p+
**FileAccess.java ]1!" q40)]
*//文件访问(定位，写) 3%Y:+%VE
package NetFox; @z@%vr=vX
import java.io.*; D!&(#Vl _
P"vrYom
*HKw;I
public class FileAccessI implements Serializable{ >aVgI<
]b4IO4T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OldOc5D
RandomAccessFile oSavedFile; "313eeIt%i
long nPos; GI%&.Vd
F_ F"3'[
cszvt2BIg
public FileAccessI() throws IOException Vx_33";S\
{ @ma(py
this("",0); \Rny*px
} (&:gD4.
bx3Q$|M?
<gp?}Lk
public FileAccessI(String sName,long nPos) throws IOException XNJ4T]><
{ t7+A!7b{
oSavedFile = new RandomAccessFile(sName,"rw"); 'X?xn@?
this.nPos = nPos; jo`ZuN{
oSavedFile.seek(nPos); _VrY7Mz:r
} PXb$]HV
iEvQ4S6tD
U[C4!k:0
public synchronized int write(byte[] b,int nStart,int nLen) ;m(iKwDt
{ [oLV,O|s|j
int n = -1; Gnkar[oa&
try{ .Nn11F< d
oSavedFile.write(b,nStart,nLen); 3z+l-QO8
n = nLen; R?xb1yc7_
} `S {&gl
catch(IOException e) `geHSx_
{ @UD:zUT)F
e.printStackTrace (); ~r--dU
} W:]FYC
Ww7Ya]b.k
I~GF%$-G
return n; iM+`7L'
} =kd$??F
9njl,Q:
"z~ba>,-\
} ux;?WPyr
[^5\Ww
ks4`h>i
/* L|=5jn9 :
**SiteInfoBean.java Y2H-D{a27
*/ r\Nfq(w
package NetFox; CXlbtpK2k
qkb'@f=
NX @FUct;
public class SiteInfoBean { PMzPj,
(`tRJWbdz
:L[>!~YG_n
private String sSiteURL; //Site's URL aLO^>",
private String sFilePath; //Saved File's Path PVCoXOqh
private String sFileName; //Saved File's Name @R[{
private int nSplitter; //Count of Splited Downloading File JB_fS/I
sXIYl% d
7;'33Bm*
public SiteInfoBean() y~SVD@
{//nSplitter的缺省值为5 ,erw(7}'.
//default value of nSplitter is 5 ;5[KZ8j6Y
this("","","",5); 8H!QekQZ]\
} rpR${%jc
}#XFa#
[0H0%z#tU&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) oo5=5s6 3}
{ c`a(
sSiteURL= sURL; G.W !
sFilePath = sPath; 8t-GsjHb
sFileName = sName; zKJ2~=
this.nSplitter = nSpiltter; .|UQ)J?s
{Cx5m
xUo6~9s7
} *IG$"nu
{Mx(|)WkL
o5 L^
public String getSSiteURL() ud1M-lY\U
{ n<I{x^!
return sSiteURL; bF'rK'',
} x]~TGzS
bzgC+yT
._mep\#.:
public void setSSiteURL(String value) %bW_,b
{ #/)t]&n
sSiteURL = value; K2
} ~wc:/UM|
a?c&#Jl
I2cz:U7
public String getSFilePath() N##`
{ (\V i_
return sFilePath; PnlI {d
} 'M90Yia
;JW_4;-
c8RJOc4X
public void setSFilePath(String value) $6hPTc<C
{ 6b|?@
sFilePath = value; E8Dh;j
} ny={OhP-
d[ N1zQW
,Kit@`P%
public String getSFileName() ]I*c:(qwu
{ C@rGa7
return sFileName; tYS4"Nfb+
} 4E'9;tA3l
d_RgKdR )k
s}D>.9
public void setSFileName(String value) B@,9Cx564
{ d|`Ll
sFileName = value; S}m_XR]
} q2GW3t
p7?
'6KvB
public int getNSplitter() "L~(%Nx3
{ f)I5=Ijy(
return nSplitter; D$>_W,*V
} D}-.<
95DEuReKi
(!j#u)O
public void setNSplitter(int nCount) L9x-90'q,
{ ,Q`qnn&
nSplitter = nCount; &W `xZyb3
} t6+m` Kq
} 0mw1CUx9K
Onmmcem
xO$P C,
/* n*4`Tduu^
**Utility.java \P\Z<z7jy
*/ 8*ZsR)!
package NetFox; BD g]M/{
:<%bAn
>rG>Bz^Pu
public class Utility { yNu_>!Cp5
4aayMS!#
^xo<$zn
public Utility() }r}*=;Ea
{ jX53 owZ
)U^=`* 7
^E&PZA\,;
} b*|~F
>mGH4{H
//线程睡眠 D0. )%
public static void sleep(int nSecond) _=v#"l
{ 8tvmqe_G
try{ ?vXgHDs^T
Thread.sleep(nSecond); b0P3S!E
} K+g[E<x\=
catch(Exception e) Hq@+m!
{ j50vPV8m
e.printStackTrace (); ]TV_p[L0B
} 0.GFg${v`
} ?HEqv$n
T:}Q3
//日志 'K[ml ?_
public static void log(String sMsg) G5ATR<0m
{ y]9R#\P/
System.err.println(sMsg); (f/(q-7VWt
} 5#Er& 6s
blc?[ [,!
]4:QqdV
public static void log(int sMsg) kR]P/4r
{ Y2|i>5/|<
System.err.println(sMsg); ]HKt7 %,
} 0B6!$) *-i
} /ViY:-8s
w OL,LU
E^8|xT'h6
/* D 0Xl`0"'
**TestMethod.java I{Du/"r#
*/ 84ij4ZYe
package NetFox; oEIpv;:_
h5?^MRZS
c3]t"TA,
public class TestMethod { hBgE%#`s
Z|$#
R%r bysP
public TestMethod() (s8b?Ol/
{ ///xx/weblogic60b2_win.exe OB>Hiy
try{ >ohCz@~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y oW~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x&B&lFmo8
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6w.E Sm
fileFetch.start(); CKAd\L
} bY_'B5$.^2
catch(Exception e){e.printStackTrace ();} :saP :&
}[+uHR6L
fA=Z):w
} 7q0_lEh
>$q
by[i"!RCu
public static void main(String[] args) >o#wP
{ mS}x2&
new TestMethod(); ~"2@A F
} *yq]
} .{a2z*o
点击下载更多相关资料