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)); _zkTx7H
} l{Et:W%|
for(int i=0;i<nEndPos.length-1;i++) 8Vy/n^3)
{ m95] z18T'
nEndPos = nStartPos[i+1]; J&bMox
} F_&H*kL L3
nEndPos[nEndPos.length-1] = nFileLength; )d>Dcne
} ,ZVhL* "
} &[ ,*
dM-~Qo
n(.L=VuXn
//启动子线程 \0Ba?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [<sN"
for(int i=0;i<nStartPos.length;i++) TAq[g|N-;
{ g>g*1oS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )2 b-3lz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2Z?l,M~
nStartPos,nEndPos,i); $&Z<4:Flc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j8%Y[:~D
fileSplitterFetch.start(); nUK;M[
} gYloY=.Z$'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gX|\O']6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >vXS6`;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^a$L9p(
nEndPos = " + nFileLength); 8tO.o\)h
// fileSplitterFetch[nPos.length-1].start(); q{+}0!o
TPLv]$n
O)"Z%B
//等待子线程结束 lYey7tl{
//int count = 0; 6n;? :./
//是否结束while循环 4%4Yqx )
boolean breakWhile = false; nW`] =
^V7)V)Z;0
|pBvy1e4)
while(!bStop) P0RtS1A
{ >Bu_NoM
write_nPos(); ]]y4$[|L
Utility.sleep(500); `|PhXr
breakWhile = true; NN5G '|i
ZG?e%
5RP5%U
for(int i=0;i<nStartPos.length;i++) E,fbIyX
{ u>:j$@56
if(!fileSplitterFetch.bDownOver) +O)ZB$w4
{ a5&[O
breakWhile = false; t>x!CNb'C
break; ,!X:wY}dW
} P76gJ@#m
} <sX_hIA^Fx
if(breakWhile) yZ]?-7
break; [[xnp;-;
I:0dz:T7*
a-AA$U9hj
//count++; *$3p3-
//if(count>4) V{~~8b1E
// siteStop(); c7R&/JV
} c=^69>w
.EvP%A m
B1]FB|0's
System.err.println("文件下载结束！"); c[$i)\0
} )|#ExyRO
catch(Exception e){e.printStackTrace ();} cQsSJBZ[v5
} 'v=BAY=Ef
ap,zC)[
vu&ny&=`
//获得文件长度 [^XD@
public long getFileSize() c`N_MP
{ U[:=7UABU?
int nFileLength = -1; +{}p(9w@
try{ PnL?zae
URL url = new URL(siteInfoBean.getSSiteURL()); w2jB6NQX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zy.v[Y1!
httpConnection.setRequestProperty("User-Agent","NetFox"); b<[]z,
~M1T @Mv
0DN&HMI#
int responseCode=httpConnection.getResponseCode(); *}_i[6_\E
if(responseCode>=400) 19RbIG/X
{ b@sq}8YD|z
processErrorCode(responseCode); \Ym!5,^o
return -2; //-2 represent access is error AP8J28I
} 6j!a*u:}"
@}uo:b:Q
44KWS~
String sHeader; j&b<YPZ
_Y$v=!fY&
<p+7,aE_
for(int i=1;;i++) RWoVN$i>
{ R/ x-$VJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i8DYC=r
//Utility.log(in.readLine()); uaxkGEXr
sHeader=httpConnection.getHeaderFieldKey(i); j 20mZ
if(sHeader!=null) =vDpm,
{ l{VJaZ $M
if(sHeader.equals("Content-Length")) 07:h4beT
{ CK_\K,xVT
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V343IT\
break; 85Kf>z::c
} XhN?E-WywQ
} {7q8@`Oa
else yVJ)JhV
break; /Ao.b|mm
} sDu&9+
} ?,C'\8'
catch(IOException e){e.printStackTrace ();} f9hH{(A
catch(Exception e){e.printStackTrace ();} Ri}JM3\J
Uo[`AzD3
]iZ-MG)J
Utility.log(nFileLength); Q8h=2YL
9WHarv2@
3E>]6
return nFileLength; IVeA[qA0
} wy:euKB~
w(ic$
w;J#+ik
//保存下载信息（文件指针位置） yA`,ns&n
private void write_nPos() KqNsCT+j
{ 2d<`dQY{l3
try{ Xob(4
output = new DataOutputStream(new FileOutputStream(tmpFile)); QqcAmp
output.writeInt(nStartPos.length); M?kXzb\O
for(int i=0;i<nStartPos.length;i++) F$9+WS`c
{ 2%MS$Fto
// output.writeLong(nPos); |Z$)t%'
output.writeLong(fileSplitterFetch.nStartPos); qSaCl6[Do
output.writeLong(fileSplitterFetch.nEndPos); tMo=q7ig
} APU~y5vG (
output.close(); pvRa
} HDz"i
catch(IOException e){e.printStackTrace ();} 9'KOc5@l^
catch(Exception e){e.printStackTrace ();} =S\pI
} :z$+leNH\
8P&z@E{y
-&QpQ7q1
//读取保存的下载信息（文件指针位置） NIC.c3
private void read_nPos() 9Dyy&$s
{ $us7fuKE
try{ lH"VLO2l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mk6>}z*
int nCount = input.readInt(); <u
nStartPos = new long[nCount]; D@k#'KU
nEndPos = new long[nCount]; :K!L-*>A9
for(int i=0;i<nStartPos.length;i++) (&/~q:a>
{ 2,.8oa(
nStartPos = input.readLong(); 4*UKR!sr
nEndPos = input.readLong(); R]o2_r7N"}
} G@<[fO|Iam
input.close(); Su'l &]
} T\Jm=+]c!
catch(IOException e){e.printStackTrace ();} @^HZTuP2;
catch(Exception e){e.printStackTrace ();} Tb] h<S
} \x"BgLSE
\JNWL yw
K{FBrh
private void processErrorCode(int nErrorCode) ]_4HtcL4
{ ,~NJ}4wP
System.err.println("Error Code : " + nErrorCode); .;&4'ga4
} ,@Elw>^
5[^Rf'wy
BIT<J5>
//停止文件下载 tpP68)<ns
public void siteStop() 0rc'SEl
{ }jg,[jw_"X
bStop = true; 6h\; U5
for(int i=0;i<nStartPos.length;i++) 5J3K3
fileSplitterFetch.splitterStop(); t\\<+^[%
Qr~yHFc1y
^K^rl9
} A.<M*[{q
} \K:?#07Wj4
//负责部分文件的抓取 "}uV=y
**FileSplitterFetch.java Ul|htB<1:
*/ YRj"]= 5N
package NetFox; Wix4se1Ac
@EH@_EwYV
M7neOQHq
import java.io.*; ket"fXqJX
import java.net.*; ?C_Y2JY
]yas]5H
DWU(ld:_
public class FileSplitterFetch extends Thread { z>spRl,dr
>W'"xK|:
.L_ Hk
String sURL; //File URL $XFFNE`%
long nStartPos; //File Snippet Start Position No]#RvEd3
long nEndPos; //File Snippet End Position fc%C!^7
int nThreadID; //Thread's ID dewN\
boolean bDownOver = false; //Downing is over <@qJsRbhK
boolean bStop = false; //Stop identical h9+76
FileAccessI fileAccessI = null; //File Access interface <{.pYrn
H`T}k+e2-N
wgZ6|)!0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /tqe:*
{ $XrX(l5
this.sURL = sURL; Y,X0x-
this.nStartPos = nStart; e:6mz\J
this.nEndPos = nEnd; lq)[
nThreadID = id; cUU"*bA#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {JW_ZJx
} 9NqZ&S
4aG}ex-s|
sQT<I]e
public void run() RIF*9=,S
{ L>,xG.oG
while(nStartPos < nEndPos && !bStop) DXfQy6k'
{ wPpern05
3:gF4(.
`W4Is~VVv
try{ 6yMaW eT
URL url = new URL(sURL); K)9f\1\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V_T~5%9Fy
httpConnection.setRequestProperty("User-Agent","NetFox"); qWI8 >my11
String sProperty = "bytes="+nStartPos+"-"; *BQy$dfE
httpConnection.setRequestProperty("RANGE",sProperty); Gk<6+.c~
Utility.log(sProperty); #vT~D>zj
iMp_1EXe
oF5~|&C
InputStream input = httpConnection.getInputStream(); v$R7"
//logResponseHead(httpConnection); mB*;>
wmit>69S
m?`$NJST
byte[] b = new byte[1024]; r7*'s
int nRead; =|q@Q`DB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P".rm0@R
{ IPlkv{^
nStartPos += fileAccessI.write(b,0,nRead); Rhh.fV3
//if(nThreadID == 1) =OooTZb:x-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'k9 1;T[
} o>\epQt~/p
rd}|^&e!Dy
79ZYRm2;
Utility.log("Thread " + nThreadID + " is over!"); lmB+S
bDownOver = true; U p: M[S
//nPos = fileAccessI.write (b,0,nRead); =2, iNn
} -2y>X`1Y
catch(Exception e){e.printStackTrace ();} B%KfB VC
} w'P!<JaZ
} h7>`:~
~01Fp;L/
mvGj !'
//打印回应的头信息 7gT^ZL
public void logResponseHead(HttpURLConnection con) &fgfCZz'
{ DX8pd5U
for(int i=1;;i++) @%$<,$=
{ h,P#)^"
String header=con.getHeaderFieldKey(i); {8J+Y}
if(header!=null) ,+E"s3NW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -2*Pm1\Z
Utility.log(header+" : "+con.getHeaderField(header)); qbQH1<yS<
else ~*ll,<L:
break; 0%]F&|
} Z`kI6
} 7cZ(gdQ/
Y f;Slps
$jv/00:&
public void splitterStop() Wj31mV
{ Z66q0wR7
bStop = true; nSh}1Arp/
} bJ9K!6s??`
X##hSGQM
*W=R:Bl!
} _.3O(?p,
5KwT(R o
%8T"h
/* !Ytr4DtM
**FileAccess.java "9yQDS:
*//文件访问(定位，写) >^%TY^7n
package NetFox; _tpqo>
import java.io.*; R3@$ao
!;;WS~no3
i?CXDuL
public class FileAccessI implements Serializable{ tD\%SiTg=b
%P-z3 0FHp
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 by0M(h
RandomAccessFile oSavedFile; Tjza3M
long nPos; 8yn}|Y9Fu
{/SLDyf%Z
RS[>7-9
public FileAccessI() throws IOException W&8)yog.
{ FTC,{$
this("",0); TSAVXng
} x9VR>ux&
AF-uTf
fs wQ*
public FileAccessI(String sName,long nPos) throws IOException oN7JNMT
{ y(0";\V
oSavedFile = new RandomAccessFile(sName,"rw"); l<=Y.P_2
this.nPos = nPos; '"14(BvW
oSavedFile.seek(nPos); 5t~p99#?
} 'J"m`a8no
7>>6c7e
dUL3UY3
public synchronized int write(byte[] b,int nStart,int nLen) DZ~qk+,I
{ \1b!I)T9
int n = -1; LHJjPf)F
try{ Z 361ko}
oSavedFile.write(b,nStart,nLen); {%Q&CQG_
n = nLen; ;UG]ckV-
} BX=YS)
catch(IOException e) F~tT5?+
{ SN/ e41
e.printStackTrace (); |]8Hh>
} Y1Qg|U o
_0(Bx?[h
Pf?y!dK<
return n; *%wfR7G[B
} E||[(l,b
aL%amL6CX
KZ;Q71
} ]K(>r#'nH
}D>nXhO&
@,{', =L6
/* z}:|is)?
**SiteInfoBean.java Z:(yX0U,[
*/ _@Le MNv
package NetFox; cy-Bhk0H
t^zmvPDK
">^O{X\
public class SiteInfoBean { w0iv\yIRQ
HKZD*E((
7$&3(#!N
private String sSiteURL; //Site's URL }^np
private String sFilePath; //Saved File's Path UBy< vwnU
private String sFileName; //Saved File's Name PtT=HvP!k
private int nSplitter; //Count of Splited Downloading File W{!GL
Eax^1 |6
ni$S@0
public SiteInfoBean() _H+|Ic
{//nSplitter的缺省值为5 UfUboxT
//default value of nSplitter is 5 g-Y2U}&
this("","","",5); ZfYva(zP{Q
} g:sn/Zug]
6*n<emP
`pzXh0}|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rL/e
{ ?-`G0(
sSiteURL= sURL; v9qgfdBS5
sFilePath = sPath; @GpM4>:
sFileName = sName; dE[nPtstb
this.nSplitter = nSpiltter; &eHhj9
|_^A$Hv
I*Q^$YnM
} N5%zbfKM
9j;L-
~;*SW[4
public String getSSiteURL() SXW8p>1Jw
{ (!@ Q\P
return sSiteURL; :DlgNR`bq
} t<|S7EqIL
&(]@L\A
1dy>a=W
public void setSSiteURL(String value) 9$u'2TV
{ g5 J[ut
sSiteURL = value; z"@yE*6
} 9svnB@
y.l`NTT]<
"#a_--"k9
public String getSFilePath() 1b,,uI_
{ cx(aMcX6
return sFilePath; nf7l}^/UE
} eXqS9`zKr
d }"Dp
QKAo}1Pq
public void setSFilePath(String value) lbCTc,xT
{ Gs% cod
sFilePath = value; q@}eYQ=P|e
} !e}LB%zf
.1[[Y}
&GC`4!H
public String getSFileName() dvAvG.;U
{ wK_I"
return sFileName; "AzA|zk')"
} 0?tn.<'B8T
7eh<>X!TX
4\.1phe$a
public void setSFileName(String value) 4nfpPNt
{ 9bL`0L
sFileName = value; /"Bm1
} Nl3@i`;
~ "^]\3#
5f:Mb|.?
public int getNSplitter() }CiB+
{ %YI Xk1
return nSplitter; =2 3H/
} 43"`gF]
@o[C Xrz
/a?*Ap5"
public void setNSplitter(int nCount) |,&5.|E 7
{ \m3;<A/3n
nSplitter = nCount; L@"1d.k_
} 0<8pG:BQ
} +$hqwNh@Z@
y7;i4::A\
;<JyA3i^V,
/* p@H3NX
**Utility.java H WOl79-
*/ !f\q0Gnl
package NetFox; PfaBzi9?f
J;K-Pv+
Fo=hL
public class Utility { "pDwN$c
'Y ZYRFWXM
FY^[?lj
public Utility() dU7+rc2,CU
{ (QPfrR=J4
BrdHTk= Vy
Ye'=F
} f__r" N
dPdodjSu,!
//线程睡眠 GWNLET
public static void sleep(int nSecond) { *"I4
{ jIq@@8@o
try{ ^ di[J^
Thread.sleep(nSecond); ;\F3~rl
} Q -!,yCu
catch(Exception e) @A_bZQ@
{ DriJn`vtzq
e.printStackTrace (); mG?g
} w"Q6'/P
} JMMT886
+bG^SH2ke
//日志 YceX)
public static void log(String sMsg) /AJ#ngXz
{ /'V(F* g
System.err.println(sMsg); p7UdZOi2
} 03F%!Rm/j
"k)}qI{
Osb#<9{}
public static void log(int sMsg) :u%Jrc(W
{ 4,8=0[eRG
System.err.println(sMsg); ionFPc].
} X=i^[?C
} i`]-rM%J#
y;)j
wUGSM"~ |
/* mgIB8D+6
**TestMethod.java 7QXA*.' F
*/ j-egsKR
package NetFox; u!=9.3
O "jX|5
U*G8}W
public class TestMethod { BO#XQ,
~i)m(65:
{*gO1TZt9
public TestMethod() LciSQ R!
{ ///xx/weblogic60b2_win.exe 3ErW3Ac Ou
try{ I<v1S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K.y2 $b/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C+,JLK
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^sLnKAN
fileFetch.start(); :L~{Q>o
} pzX684
catch(Exception e){e.printStackTrace ();} OLThi[Yn
|v,5s=}7
O5:?nD
} 5pJ)OX
V/X4WZs|i
*Nv!Kuk
public static void main(String[] args) cs'ylGH
{ (=hXt=hZ
new TestMethod(); Mw=sW5Z
} E\3fL"lM
} !H,_*u.
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