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)); &m4 \"X@
} M,t8<y4W/
for(int i=0;i<nEndPos.length-1;i++) @"kA&=0;|J
{ djPr 4Nog
nEndPos = nStartPos[i+1]; v(=fV/
} rc*&K#? B
nEndPos[nEndPos.length-1] = nFileLength; nV McHN
} HQaKG4Z
} =5%jKHo+9z
~5`rv1$
"(/|[7D)
//启动子线程 l?a(=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?qw&H /R
for(int i=0;i<nStartPos.length;i++) u|WX?@\
{ 2ADUJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %zd1\We
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7l7eUy/z
nStartPos,nEndPos,i); vf~q%+UqK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .ymR%X_k
fileSplitterFetch.start(); *2 4P T7
} ZHICpL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +sE81B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Vs8os+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y*\ M7}](
nEndPos = " + nFileLength); X&^t 8
// fileSplitterFetch[nPos.length-1].start(); \H<'W"
L`x:Y>C(
_"a(vfl#
//等待子线程结束 \@['V
//int count = 0; rd0BvQ9TK
//是否结束while循环 l8GziM{lp
boolean breakWhile = false; \?GUGs
`\q4z-<-
j"_V+)SD
while(!bStop) p."pI Bd
{ vV#Jl) A
write_nPos(); +tdt>)a
Utility.sleep(500); (~}yt.7K
breakWhile = true; 20zIO.&o
zBB4lC{q
"KW\:uc /
for(int i=0;i<nStartPos.length;i++) &>@nW!n u
{ @6 gA4h
if(!fileSplitterFetch.bDownOver) 0$}+tq+
{ uc=-+*D'I
breakWhile = false; @XDU!<N
break; ;TMH.E,h:
} z6|P]u
} E} Uy-
if(breakWhile) 6rt.ec(
break; .4_EaQ;jX
rNfua
0}PW?t76
//count++; =o{zw+|% %
//if(count>4) ',kYZay
// siteStop(); Xn$]DE/r}N
} $62ospR^Y
V`S6cmwdc\
GZXUB0W\@)
System.err.println("文件下载结束！"); uzho>p[ae
} H`),PY2
catch(Exception e){e.printStackTrace ();} WSi Utf|g
} _ 97F
l]T|QhiVd
sA3 4`ZAa
//获得文件长度 '"~|L>F%G
public long getFileSize() lb{*,S
{ N:d`L+tcc
int nFileLength = -1; !(uyqplTk
try{ )3'/g`c
URL url = new URL(siteInfoBean.getSSiteURL()); ["MF-tQ5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 22}J.'Zb
httpConnection.setRequestProperty("User-Agent","NetFox"); .9lx@6]+
_s|C0Pt
HR\yJt
int responseCode=httpConnection.getResponseCode(); < I8hy$+6
if(responseCode>=400) {/XzIOO;b
{ p!|Wp
processErrorCode(responseCode); 2[r#y1ro
return -2; //-2 represent access is error k U*\Fa*E
} d=xU f`^
8!b#ez
8g(%6 ET
String sHeader; ~BrERUk
c/x ^I{b*
t$]lK6
for(int i=1;;i++) iKLN !QR
{ Wl;F]_|*(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (t>BO`,
//Utility.log(in.readLine()); jNaK]
sHeader=httpConnection.getHeaderFieldKey(i); $MfHA~^
if(sHeader!=null) S,n*1&ogj
{ ~U~KUL|
if(sHeader.equals("Content-Length")) _?Rprmjx}
{ Y71io^td~j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *]W{83rXQ
break; ;pBSGr9
} ,kpkXK
} Zh{Pzyp
else yJppPIW^
break; -%5*c61
} (pREo/T
} &h`s:Y
catch(IOException e){e.printStackTrace ();} [Sg1\UTl
catch(Exception e){e.printStackTrace ();} &Jk0SUk MP
8JJqEkQ
Fv.}w_
Utility.log(nFileLength); Gi6sl_"q
h-<('w:A
S'9T>&<Kn
return nFileLength; //3iai
} U;`N:~|p#
r_@;eh
Eu l,1yR
//保存下载信息（文件指针位置） (6^v`SZ
private void write_nPos() ,=Xr'7w,
{ *6df|q
try{ O:{I9V-=>s
output = new DataOutputStream(new FileOutputStream(tmpFile)); k_ UY^vz.
output.writeInt(nStartPos.length); Ra%RcUf~sh
for(int i=0;i<nStartPos.length;i++) SBzJQt@Hs
{ #i%it
// output.writeLong(nPos); Kxn/@@z>u
output.writeLong(fileSplitterFetch.nStartPos); |bQKymS
output.writeLong(fileSplitterFetch.nEndPos); i!*w'[G->Y
} q}*(rR9/Br
output.close(); [v^T]L
} CJz2.yd
catch(IOException e){e.printStackTrace ();} 5qt]~v%y
catch(Exception e){e.printStackTrace ();} zFN:C()ig
} Cf91#%:cN
b" 1a7
FF0N{bY
//读取保存的下载信息（文件指针位置） p3&/F=T;)
private void read_nPos() x{*g^f
{ WUvrC
try{ f<=<:+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S*Qip,u
int nCount = input.readInt(); A0m
nStartPos = new long[nCount]; :"5i/Cx
nEndPos = new long[nCount]; n!2"pRIi
for(int i=0;i<nStartPos.length;i++) AME3hA
{ )^qM%k8
nStartPos = input.readLong(); cV\(Z6u
nEndPos = input.readLong(); xdFm-_\-
} -y5^xR
input.close(); YiJnh47
} }%c2u/PQ
catch(IOException e){e.printStackTrace ();} ^ |z|kc
catch(Exception e){e.printStackTrace ();} O:IU|INq8
} JF!JY( U,
yS^";$2Tc
mKugb_d?
private void processErrorCode(int nErrorCode) b|^g51v
{ R9A8)dDz
System.err.println("Error Code : " + nErrorCode); ]i(tou-[i
} (dd+wx't
v8Vw.Ce`f
;PCnEs
//停止文件下载 NoTEbFrV
public void siteStop() Se.\wkl#Y
{ _PLY<i2vr
bStop = true; VCSHq&p8
for(int i=0;i<nStartPos.length;i++) i ?&t@"'
fileSplitterFetch.splitterStop(); twv|,kM
:hJHjh
n+QUT
} Ebw1 %W KC
} cKJf0S:cx-
//负责部分文件的抓取 cXU8}>qY7
**FileSplitterFetch.java @<=xfs
*/ Uy2NZ%rnt
package NetFox; "(zvI>A
)h6hN"#V5
gHdNqOy c
import java.io.*; Px{Cvc
import java.net.*; e/Wrm^]y
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jd8`D6|Z
public class FileSplitterFetch extends Thread { f4UnLig
*oopdGue
ZUePHI-dP
String sURL; //File URL UF0W%Z
long nStartPos; //File Snippet Start Position ,n<t':-
long nEndPos; //File Snippet End Position 'n4Ro|kA
int nThreadID; //Thread's ID s~ ||Vv!
boolean bDownOver = false; //Downing is over nr7#}pzo
boolean bStop = false; //Stop identical me:~q#k
FileAccessI fileAccessI = null; //File Access interface Q&+Jeji
F*m^AFjs
a~q_2S]h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nGQc;p5;
{ O'm><a>8
this.sURL = sURL; O<7Q>m
this.nStartPos = nStart; t"x 8]Gy
this.nEndPos = nEnd; ,I6jfXI4
nThreadID = id; M8dv y!D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 uu ahR
} jr[(g:L
)[fjZG[
[Jv0^"]
public void run() "yaz!?O>
{ OAJGwm
while(nStartPos < nEndPos && !bStop) rQmDpoy=
{ Y-!~x0-H
|osu4=s|
XJg8-)T#
try{ j/.$ (E
URL url = new URL(sURL); \ #<.&`8B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G>Fk )
httpConnection.setRequestProperty("User-Agent","NetFox"); \WS2g"(
String sProperty = "bytes="+nStartPos+"-"; }L mhM
httpConnection.setRequestProperty("RANGE",sProperty); ffoL]u\
Utility.log(sProperty); <A|X4;
3y^PKIIrt
%Ms"LoK
InputStream input = httpConnection.getInputStream(); H<_BnT#
//logResponseHead(httpConnection); dbn9t7'{
L\0;)eJ#M
LLyw9y1
byte[] b = new byte[1024]; %+ln_lgD:
int nRead; aa|u*afWQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UWU(6J|Fk
{ ] V|hDU=t
nStartPos += fileAccessI.write(b,0,nRead); xgDd5`W
//if(nThreadID == 1) 5OEo(&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g)?Ol
} CD^C}MB
I0iTa99K
k=]#)A(#C
Utility.log("Thread " + nThreadID + " is over!"); -M]B;[^
bDownOver = true; $Lj~ge3#
//nPos = fileAccessI.write (b,0,nRead); >+,w2m@0
} uqz HS>GM
catch(Exception e){e.printStackTrace ();} ?'_Ty`vT
} Cws;6i*=@
} s!k7Wwj
G5WQTMzf&
d]A.=NAc
//打印回应的头信息 PP*6nW8
public void logResponseHead(HttpURLConnection con) u<L<o2
{ Sg%h}]~
for(int i=1;;i++) wnioIpRkh
{ KA $jG{yq
String header=con.getHeaderFieldKey(i); -VZn`6%s
if(header!=null) DWv(|gO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Lql2ry$Wa
Utility.log(header+" : "+con.getHeaderField(header)); cNbH:r"Ay
else oW}nr<G{<
break; } 6 ,m2u
} n[S-bzU^t
} LNz
./]xn
Q};n%&n&
public void splitterStop() fe!eZiE
{ <`$svM
bStop = true; mpr_AL!ZO~
} epicY
}b5omHUE%
G2$<Q+UYs?
} jz,K>
QhhL_vP
GB%kxtGD;\
/* O2pntKI
**FileAccess.java qt(+X
*//文件访问(定位，写) Hs:0j$
package NetFox; 1d$qr`
import java.io.*; t1JU_P
sX@}4[)<&
e{EC#%x_
public class FileAccessI implements Serializable{ kzE<Y
,?>{M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 NX[-Y]t
RandomAccessFile oSavedFile; ]OSq}ul
long nPos; >jU25"XI[
0g2?
a8WWFAC[
public FileAccessI() throws IOException }/w]+f*
{ m?<^b_a}
this("",0); ~8 B]
} {+~ JTrp
-uKTEG[
Ypx5:gm|J
public FileAccessI(String sName,long nPos) throws IOException 0OXl`V`w
{ A"e4w?
oSavedFile = new RandomAccessFile(sName,"rw"); 1[yy/v'q
this.nPos = nPos; YdZ9##IU3
oSavedFile.seek(nPos); #<LJns\t
} ?gsPHPUS
j.&Y'C7GOC
o%b6"_~%3
public synchronized int write(byte[] b,int nStart,int nLen) /78zs-
{ ;J@U){R
int n = -1; XS}-@5TI
try{ 216`rQ}z
oSavedFile.write(b,nStart,nLen); )x,/+R]{8l
n = nLen; 2tb+3K1
} {RGQX"k
catch(IOException e) 7lx" X0w*m
{ {Gr"lOi*@
e.printStackTrace (); r6eZ-V`4
} _1?nLx7n
XDYQV.Bv
5tI#UBha
return n; zv7)JH7EV&
} \0W0o5c$
v<Ywfb
mm9uhlV8
} =F2`X#x_j
{2%'=v
`;=-71Gn~
/* p[O\}MAd#
**SiteInfoBean.java 86pA+c+U
*/ g~ii^[W
package NetFox; %aI,K0\
i zYC0T9
ken.#>w
public class SiteInfoBean { =H`yzGt
X }`o9]y
xnC:?d
private String sSiteURL; //Site's URL @Di!~e6
private String sFilePath; //Saved File's Path VKtlAfXy~
private String sFileName; //Saved File's Name b^STegz
private int nSplitter; //Count of Splited Downloading File YQ@2p?4m
p"FWAC!
? 'qyI^m@
public SiteInfoBean() v, CWE
{//nSplitter的缺省值为5 xk
//default value of nSplitter is 5 3RX9LJGX
this("","","",5); TCFr-*x
} (q0vql
\11+~
M&jlUr&l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {!j)j6(NY
{ L PS,\+
sSiteURL= sURL; S&'?L0
sFilePath = sPath; v}J0j
sFileName = sName; fP[S.7F+No
this.nSplitter = nSpiltter; 2FW"uYA;6
1 0zw}1x
K^6d_b&
} (Hmm^MV)
gAh#H ?MM
{{Qbu}/@
public String getSSiteURL() `T+w5ONn
{ qw*) R#=
return sSiteURL; P:_bF>r ?
} 0K6My4d{
r7sA;Y\
SA#01}&p
public void setSSiteURL(String value) obGhO
{ kdWUz(
sSiteURL = value; k+%&dEE|vH
} ?(Ua+*b
734t
RH:vd|q+
public String getSFilePath() <@# g2b
{ Y]=k"]:%
return sFilePath; "hQGk
} cRMyYdJ o
: h(Z\D_
gkX7,J-0
public void setSFilePath(String value) 0VrsbkS
{ Z^}[CQ&Am
sFilePath = value; {/(.Bpld
} (t\U5-w
'Hzc"<2Y\
$hHV Ie]+
public String getSFileName() *Ojl@N
{ L+VQtp&"
return sFileName; Q)y5'u qZ
} mo3A*|U
"G-h8IN^O
kxN O9w
public void setSFileName(String value) 7AS_Aw1L
{ 98)C 7N'
sFileName = value; xmEom
} Y+o\?|q-E
[KFCc_:
q2r$j\L%
public int getNSplitter() o ^ \+Ua
{ mBJr*_p
return nSplitter; R8:5N3Fx
} jV9oTH-
qp)Wt6 k?
TpwN2 =
public void setNSplitter(int nCount) 7R7+jL,
{ Be6+YM5Cl
nSplitter = nCount; xkw=os
} dA (n,@{
} z;dRzwL
-%]1q#C>@
rQ_]%ies8
/* t,dm3+R
**Utility.java Ssuz%*
*/ Xz)qtDN|(
package NetFox; <5mv8'{L
w3"L5;oH
`Oi#`lC\
public class Utility { A)4XQF
^a`3)WBv8
dHTx^1
public Utility() -Ci&h
{ 52 Qr
)`(]jx!
SASLeGaV
} jI0gf&v8
c|`$ h
//线程睡眠 Zhv%mUj~
public static void sleep(int nSecond) Ef?hkq7X<
{ 7)Vbp--b#
try{ iF Mf[qBg
Thread.sleep(nSecond); i\l}M]Z#
} <G|i5/|7
catch(Exception e) i9De+3VqKK
{ :fwtPvLo
e.printStackTrace (); zeuj
} K6 >\4'q
} 8PH4v\tJEK
mNacLkh[
//日志 0ug&HEl_w
public static void log(String sMsg) gpf0-g-X
{ ;3wO1'=
System.err.println(sMsg); $H[q5(_~
} 5O d]rE
p4MWX12
'8\9@wzv
public static void log(int sMsg) b=xn(HE8|
{ $,]U~7S
System.err.println(sMsg); ~Gz9pBv1
} e3W~6P
} &Jb\}c}
dr}PjwW%
PZJ9f8V
/* f+hHc8g
**TestMethod.java );VuZsmi
*/ T]Ai{@i
package NetFox; ls&H oJ7
{QylNC9
mB"I(>q*M
public class TestMethod { t"YsIOT:O"
!OY}`a(z
tE{M
public TestMethod() e2NK7
{ ///xx/weblogic60b2_win.exe d6'G 7'9
try{ pvUV5^B(M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jq*`| m;Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #"rK1Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); `R:W5_n
fileFetch.start(); zD<W`_z
} <{bxOr+
catch(Exception e){e.printStackTrace ();} Q2- lHn^L:
sH;_U)ssH
7+hF1eoI
} isd-b]@:Lc
TUC)S&bC
YfB)TK\W9/
public static void main(String[] args) 85H\v_[
{ u "jV#,,
new TestMethod(); RU4X#gP4Vh
} (@5`beEd
} (^y"'B
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