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)); **69rN
} {M,,npl
for(int i=0;i<nEndPos.length-1;i++) TW !&p"Us+
{ hdTzCfeZ5@
nEndPos = nStartPos[i+1]; %;#^l+UB
} E.1J2Ne
nEndPos[nEndPos.length-1] = nFileLength; MX@IHc
} !w BJ,&E
} TAjh"JJIV
(EPsTox
fs/*V~@
//启动子线程 j}b\Z9)!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QMv@:Eo
for(int i=0;i<nStartPos.length;i++) `y#UJYXQE
{ UH7jP#W%=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z{?G.L*/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), s3Cc;#
nStartPos,nEndPos,i); Jk,;JQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5zON}"EC
fileSplitterFetch.start(); 8p[)MiC5W^
} Vh>Z,()>>@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p~LrPWHSTP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n~VD uKn9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <nEi<iAY>U
nEndPos = " + nFileLength); f6$b s+oP
// fileSplitterFetch[nPos.length-1].start(); E7-@&=]v
A!^q J#
&^4++
//等待子线程结束 qZ@s#UiB
//int count = 0; w3jO6*_ M
//是否结束while循环 vq34/c^
boolean breakWhile = false; r(gXoq_w
!?Wp+e6
4&l10fR5
while(!bStop) !A48TgAeE
{ iiK]l
write_nPos(); @JdZ5Q
Utility.sleep(500); Haqm^Ky$
breakWhile = true; >:lnt /N3
e}1uz3Rh
hMtf.3S7c
for(int i=0;i<nStartPos.length;i++) s+>:,U<A
{ n]he-NHP
if(!fileSplitterFetch.bDownOver) +^;JS3p@\
{ <$JaWL
breakWhile = false; (p%>j0<
break; A_KW(;50
} y(K" -?
} ~i 7^P9
if(breakWhile) K_&4D'
break; QY== GfHt
Y3Q9=u*5
$ImrOf^qt
//count++; 4`,j=3
//if(count>4) Dc)dE2
// siteStop(); 1^gl}^|B
} Z1"v}g
hpU2
2;w*oop,O
System.err.println("文件下载结束！"); @IXsy
} ->N8#XH2=
catch(Exception e){e.printStackTrace ();} >rvQw63\
} CirZ+o
U(x]O/m
jlxpt)0i
//获得文件长度 2#k5+?-c61
public long getFileSize() H/}]FmjN
{ NVRLrJWpp
int nFileLength = -1; *?MGMhE
try{ fDLG>rXPT
URL url = new URL(siteInfoBean.getSSiteURL()); .ji_nZ4.+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ha)ANAD
httpConnection.setRequestProperty("User-Agent","NetFox"); +@r*}
f5`g
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int responseCode=httpConnection.getResponseCode(); o=1X^,
if(responseCode>=400) JfPD}w
{ G}p\8Q}'
processErrorCode(responseCode); ++E3]X|
return -2; //-2 represent access is error Z@r.pRr'
} {5 sO
$q 2D+_
c [5KG}
String sHeader; NF? vg/{
CD8}I85K
mx=BD'
for(int i=1;;i++) vhhC> 7
{ Q$fmD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A@Dw<.&_I
//Utility.log(in.readLine()); sq'Pyz[[
sHeader=httpConnection.getHeaderFieldKey(i); YID4w7|
if(sHeader!=null) c_>f0i
{ ?R$&Xe!5
if(sHeader.equals("Content-Length")) p'om-
{ mml z&h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x,'!eCKN
break; z<5m fAm
} =Qn ;_+Ct
} $.bBFWk
else 9H%X2#:fH
break; h;0S%ZC
} VJS8)oI~
} +$Rt+S BD
catch(IOException e){e.printStackTrace ();} )(@Hd
catch(Exception e){e.printStackTrace ();} 7hcNf,
/Ju;MeE9
zLJ/5&
Utility.log(nFileLength); 1m.W<
3g6j?yYqb
Ox@P6|m
return nFileLength; ^I+)o1%F
} *2GEnAZb7n
CoA6
QMZ)-ty"
//保存下载信息（文件指针位置） v~Y^r2
private void write_nPos() +[tP_%/r'^
{ uyY|v$FM
try{ &@3H%DP}Ql
output = new DataOutputStream(new FileOutputStream(tmpFile)); |p-t%xDdr
output.writeInt(nStartPos.length); C/-63O_
for(int i=0;i<nStartPos.length;i++) vEn4L0D
{ M4W5f#C5Ee
// output.writeLong(nPos); Rx+p.
output.writeLong(fileSplitterFetch.nStartPos); k]I0o)+O.
output.writeLong(fileSplitterFetch.nEndPos); nb>7UN.9
} ivz{L-
output.close(); -(bkr+N
} 9rA=pH%<>B
catch(IOException e){e.printStackTrace ();} 1u9LdkhnY
catch(Exception e){e.printStackTrace ();} p"U,G -_
} .e3+s*
S1?-I_t+]
s@7H1)U
//读取保存的下载信息（文件指针位置） )sT> i
private void read_nPos() /7YF mI/0
{ ]H1I,`=@
try{ =3v]gOcO
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LA)[ip4
int nCount = input.readInt(); %?Ev|:i`@
nStartPos = new long[nCount]; qQH]`#P
nEndPos = new long[nCount]; \~_9G{2?
for(int i=0;i<nStartPos.length;i++) f@c`8L@g
{ pt}X>ph{
nStartPos = input.readLong(); wLH] <k
nEndPos = input.readLong(); VzKW:St
} 10U9ZC
input.close(); 0MdDXG-7
} YGsWu7dG
catch(IOException e){e.printStackTrace ();} /ID?DtJ
catch(Exception e){e.printStackTrace ();} |*0<M(YXN
} Ho *AAg
Dmu/RD5X:
*~x/=.}
private void processErrorCode(int nErrorCode) XSZ k%_
{ Ny%(VI5:
System.err.println("Error Code : " + nErrorCode); }_68j8`
} ~Onoe $A[<
ih;]nJ]+-
,1"KHv
//停止文件下载 }O4^Cc6
public void siteStop() q')R4=0 K
{ fP `b>]N_
bStop = true; W!&vul5
for(int i=0;i<nStartPos.length;i++) qC?:*CXH
fileSplitterFetch.splitterStop(); b 'pOJS
J>bJ 449B
6}oXP_0U
} ,9o"43D:a|
} dB5b@9*
//负责部分文件的抓取 ok4@N @
**FileSplitterFetch.java 1{r)L{]
*/ }7.PH'.8
package NetFox; ;y2/-tL?
}x wu*Zx
B[4KX
import java.io.*; >L 0_dvr
import java.net.*; h^o{@/2
E3iW-B8u8
:B:"NyPA
public class FileSplitterFetch extends Thread { ^:Gie
n= u&uqA*
4zo5}L`Y
String sURL; //File URL Q(oN/y3,
long nStartPos; //File Snippet Start Position 7[}xP#Z
long nEndPos; //File Snippet End Position KPj\-g'A
int nThreadID; //Thread's ID =HlQ36;*
boolean bDownOver = false; //Downing is over 7fba-7-P
boolean bStop = false; //Stop identical w2'f/
FileAccessI fileAccessI = null; //File Access interface e;[F\ov%
Pw61_ZZ4B\
ynhmMy%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V:c;-)(
{ 8Bjib&im
this.sURL = sURL; c. 2).Jt,
this.nStartPos = nStart; ML>[^F
this.nEndPos = nEnd; 8!Ww J Oe
nThreadID = id; u[ Yk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '5|h)Q5
} |]X
9Q+'n$s0^
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public void run() k>g_Z`%<
{ -#HA"7XOE
while(nStartPos < nEndPos && !bStop) hs$GN]
{ Rw:*'1
Y1J=3Y
ssN6M./6
try{ ktpaU,%
URL url = new URL(sURL); 6'Worj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E}nH1
httpConnection.setRequestProperty("User-Agent","NetFox"); ^*Yh@4\{JH
String sProperty = "bytes="+nStartPos+"-"; ^kB8F"X
httpConnection.setRequestProperty("RANGE",sProperty); $H9%J
Utility.log(sProperty); J:zU,IIJ
Q{5kxw1ZF
3skC$mpJHw
InputStream input = httpConnection.getInputStream(); ,~]tg77
//logResponseHead(httpConnection); %s(k_|G+4
"pRtczxOgR
S-|)QGxV6
byte[] b = new byte[1024]; ,^. 88<
int nRead; k+ty>bP=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) D,k"PaLP
{ Y/ .Z.FD`
nStartPos += fileAccessI.write(b,0,nRead); RpD=]y!5_
//if(nThreadID == 1) T"DlT/\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^8AXxE
} OD6\Mr2=
|* ;B
ub\MlSr
Utility.log("Thread " + nThreadID + " is over!"); h*u
bDownOver = true; tE`u(B,
//nPos = fileAccessI.write (b,0,nRead); [c|]f_ZdK
} &bfA.& `
catch(Exception e){e.printStackTrace ();} &-B^~M*??
} m4l& eEp
} WL?\5?G9l
rcC<Zat,|
2vWx)Drb6
//打印回应的头信息 .Lsavpo
public void logResponseHead(HttpURLConnection con) }%_ b$
{ \}"$ ?d'f
for(int i=1;;i++) 9|gr0&#~j
{ 2h1vVF3
String header=con.getHeaderFieldKey(i); t_$2CRG#
if(header!=null) "C{}Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .xm.DRk3
Utility.log(header+" : "+con.getHeaderField(header)); vRHd&0
else xk5@d6Y{r
break; HV{wI1
} m0;CH/D0
} P;ci9vk
+ |#O@k
c_'OPJ
public void splitterStop() \Ani}qQ%|
{ |m^k_d!d
bStop = true; G2Qlt@.T
} nwF2aRNV
@c;|G$E@3
J:V6
} {_ i\f ]L
Kk-S}.E
G <i@ 5\#
/* iiS-9>]/
**FileAccess.java ]);%wy{Ho
*//文件访问(定位，写) Hn%xDJ'
package NetFox; (2^gVz=j
import java.io.*; 2[O&NdP\Zk
/2=#t-p+
%&w3;d;c
public class FileAccessI implements Serializable{ e} P I^bc
06c>$1-?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OHb[qX\
RandomAccessFile oSavedFile; +RYls|f
long nPos; '":lB]hS
]pNvxXbeW
1+jAz`nA:T
public FileAccessI() throws IOException qQ?"@>PALD
{ -y8`yHb_
this("",0); =E.t`x=
} d(:8M
4,CXJ2
}dWq=)*
public FileAccessI(String sName,long nPos) throws IOException o7sT=x9
{ ->y J5smtY
oSavedFile = new RandomAccessFile(sName,"rw"); }NzpiY9
this.nPos = nPos; ~M7y*'oY
oSavedFile.seek(nPos); LSGBq
} GzI yP(U
*KV0%)}sbL
#xQr<p$L6
public synchronized int write(byte[] b,int nStart,int nLen) p~BRh
{ R3;Tk^5A
int n = -1; CohDO
try{ smRE!f*q
oSavedFile.write(b,nStart,nLen); clL2k8VS
n = nLen; qB0E_y)a
} {B?Wu3-
catch(IOException e) !'&n-Q
{ jv%kOovj
e.printStackTrace (); 19Mu61
} {=!b/l;@
QLEKsX7p>
ktFhc3);!
return n; k@f g(}6
} qln3 k`
p?);eJtV/
beRVD>T
} r&R B9S@*h
/H(? 2IHC
cDFO;Dr
/* %)|9E>fP]N
**SiteInfoBean.java 52 fA/sx
*/ Crho=RJPR
package NetFox; %|g>%D3Z?
TDFkxB>
#LL?IRH9^
public class SiteInfoBean { zF8dKFE~
:Q $K<)[
7VqM$I
private String sSiteURL; //Site's URL /%}*Xh
private String sFilePath; //Saved File's Path u09:Z{tL;@
private String sFileName; //Saved File's Name Q<^Tl(`/N?
private int nSplitter; //Count of Splited Downloading File nrxo&9[@n
`\gnl'
E*V`":efS
public SiteInfoBean() [E!oQVY
{//nSplitter的缺省值为5 aE&,]'6
//default value of nSplitter is 5 m#PY,y
this("","","",5); Y^8C)p9r
} E.7
e;Ti&o}
!`g~F\l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hyCh9YOu)
{ ]h* c,.
sSiteURL= sURL; (@<lRA ^
sFilePath = sPath; 4)h]MOZ
sFileName = sName; )Dw,q~xgg0
this.nSplitter = nSpiltter; 8\^}~s$$A
V5sg#|&
FT#8L
} u37'~&o{U
s+,OxRVw(
JJ}0gZ
public String getSSiteURL() <>s`\ %
{ >}`:Ac
return sSiteURL; &x[E;P*Fg
} }!"A!~&
P&9Gga^I
(l-tvk4Ln
public void setSSiteURL(String value) M)'HCnvs'
{ )6,de2Pb
sSiteURL = value; yj;sSRT
} y.#")IAF
dv8>[#
U3T#6Rptl
public String getSFilePath() cC=[Saatsf
{ Xu<k3oD7
return sFilePath; f&eK|7J_Yf
} WG6FQAo^8
W-x?:X<}
\ e\?I9
public void setSFilePath(String value) {QcLu"?c
{ gVq;m>\|F
sFilePath = value; 4L ;% h
} WHsgjvh"
tBq nfv
pm*xb]8y
public String getSFileName() k9:{9wW
{ y.e^hRKb
return sFileName; SB1upTn
} @.b+av4J
A+::O@_s
%_+2@\
public void setSFileName(String value) Mn9dqq~a
{ C8[&S&<_<
sFileName = value; i5Zk_-\#H
} :=/85\P0SU
i@P)a'W_
<,Ue 0
public int getNSplitter() ?ooe'V@
{ wfU7G[
return nSplitter; l>Z5 uSG
} .z)%)PVV
w[9|cgCY
Bg&i63XL$$
public void setNSplitter(int nCount) 0Fk5kGD,&K
{ :*ing
nSplitter = nCount; 0y 7"SiFY
} -BRc8 /
} xIxn"^'
sm0xLZ
5b!vgm#])
/* J8S'/y(LE<
**Utility.java fBRo_CU8!
*/ 4]h =yc R
package NetFox; D2](da:]8)
N}pw74=1
[q/Abz'i
public class Utility { H<v'^*(
rqdE6y+^
cxA^:3
public Utility() gZLP\_CL
{ IhA5Wt0j
7![,Q~Fy
M,/mE~
} o*DN4oa)
rG4';V^q
//线程睡眠 MS\>DW
public static void sleep(int nSecond) K8>zF/# +
{ BybW)+~
try{ 85n1eE
Thread.sleep(nSecond); D}dn.$
} tNGp\~
catch(Exception e) |?qquD 4=
{ }._eIx"
e.printStackTrace (); A6:es_
} k"NVV$;
} DE%KW:Hug
~-EOjX(X'E
//日志 K[ (NTp$E
public static void log(String sMsg) <F}_ /q1
{ 5Yl<h)1
System.err.println(sMsg); }dp=?AFg
} 2.%.Z_k)
^C_#<m_k
ppZDGpp
public static void log(int sMsg) H *[_cqnv
{ IB[)TZ2m
System.err.println(sMsg); i'9vL:3
} ~~v3p>zRr
} ?Lyxw]
p?B=1vn-2
2Ou[u#H
/* gW-V=LV (
**TestMethod.java 'yL%3h _@
*/ Ag&0wN+jTM
package NetFox; t^6dzrF
=&,]Z6{>
+pR[U4$
public class TestMethod { i%/Jp[e\W>
LG<J;&41~S
J@4Bf
public TestMethod() xYmxc9)2
{ ///xx/weblogic60b2_win.exe Wn(6,MDUN
try{ kO|L bQ@=q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); } \XfH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `}mcEl
SiteFileFetch fileFetch = new SiteFileFetch(bean); f7=((5N
fileFetch.start(); NMa} <
} p(~Yx3$*
catch(Exception e){e.printStackTrace ();} i(iXD
"f "6]y
0URji~?|x
} c&AygqN
(CsD*U`h
qMLD)rL
public static void main(String[] args) DV _2P$tT|
{ .u4 W /
new TestMethod(); 7T1=q{#M
} -?mfE+kt
} Z/t+8;TMR,
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