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)); xLxXc!{J5
} =L,s6J8_'
for(int i=0;i<nEndPos.length-1;i++) i2. +E&3v
{ %gK@R3p
nEndPos = nStartPos[i+1]; !GB\-(
} > -P UY
nEndPos[nEndPos.length-1] = nFileLength; asDk@Gcu
} ;WydXQ}Q^
} eIZ7uSl
yQAW\0`
Y nD_:ZK
//启动子线程 :c4iXK0_^?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IUB#Vdx
for(int i=0;i<nStartPos.length;i++) mGss9eZa
{ ]!@z3Hv3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rG#o*oA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )uj:k*`)
nStartPos,nEndPos,i); C[E[|s*l
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6j*L]Sc
fileSplitterFetch.start(); >K|<hzZ
} :Ma=P\J W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ORVFp]gG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c[p>*FnP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >XTDN
nEndPos = " + nFileLength); ,\YlDcl':0
// fileSplitterFetch[nPos.length-1].start(); <+7]EwVcn^
BHmmvbM#Qm
qDG{hvl[1r
//等待子线程结束 Pu|PIdu!08
//int count = 0; (R'GrN>
//是否结束while循环 g8=j{]~C
boolean breakWhile = false; }>q%##<n
Uq}FrK}
#6fQ$x(F#j
while(!bStop) $&fP%p
{ A_h|f5
write_nPos(); \nfjz\"R?b
Utility.sleep(500); ){-Tt`0(u
breakWhile = true; Ge'[AhA
`S`,H
$N !l-lu=
for(int i=0;i<nStartPos.length;i++) @u@N&{b5"
{ \`ya08DP(
if(!fileSplitterFetch.bDownOver) l(irNKutgo
{ o|Q:am'H
breakWhile = false; T^z
break; B^7B-RBi0
} I_?+;<n
} 1/JtL>SKE
if(breakWhile) 9i6z p'
break; )JNUfauyT
bcM65pt_C
,.<[iHC}9
//count++; B=?m_4\$m
//if(count>4) Zqo
// siteStop(); o\TXWqt
} /$EX-!ie
$,b1`*
-0I]Sm;$
System.err.println("文件下载结束！"); Rcn6puZt
} `, lnBP3D"
catch(Exception e){e.printStackTrace ();} wBuos}/
} 3]46qk'
^ gy"$F3{`
be<7Vy]j
//获得文件长度 hFW{qWP
public long getFileSize() n]3Lqe;
{ g-C)y 06
int nFileLength = -1; f9%M:cl
try{ !t;B.[U *
URL url = new URL(siteInfoBean.getSSiteURL()); !7rk>YrY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ES4[@RX
httpConnection.setRequestProperty("User-Agent","NetFox"); *#n#J[
Z2t'?N|_
5WlBec@
int responseCode=httpConnection.getResponseCode(); %%-?~rjI
if(responseCode>=400) qsA`\%]H
{ u5'jIqlU
processErrorCode(responseCode); @K=:f
return -2; //-2 represent access is error dmB _`R
} KUV(vAY,
pW7#&@AR
TPBL|^3K
String sHeader; Zra P\?
pu"m(9
U} K]W>Z
for(int i=1;;i++) .!`y(N0hc
{ \kR:GZ`{UV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .or1*-B K
//Utility.log(in.readLine()); c,yjsxETW
sHeader=httpConnection.getHeaderFieldKey(i); J4) ?hS
if(sHeader!=null) v1R t$[
{ <rKfL`8p
if(sHeader.equals("Content-Length")) FjU -t/
{ (drDC1\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &6@#W]_
break; zObrp
} TOH+JL8L
} -d*zgP
else nb30<h
break; 0en Bq>vr
} Pb]EpyAW
} WSsX*L
catch(IOException e){e.printStackTrace ();} F97HFt6{
catch(Exception e){e.printStackTrace ();} _SQQS67fu"
g7l?/p[n
w(N$$
Utility.log(nFileLength); #xoFcjRE
1sIPhOIys
}m -A #4.
return nFileLength; ?*/1J~<(@
} 9F"^MzZ
my}l?S[2d@
,]LsX"u
//保存下载信息（文件指针位置） ;CtTdr
private void write_nPos() KW@][*\uC
{ s?yl4\]Muf
try{ bSkr:|A7
output = new DataOutputStream(new FileOutputStream(tmpFile)); !+)5?o
output.writeInt(nStartPos.length); v.!e1ke8D*
for(int i=0;i<nStartPos.length;i++) -)%gMD~z1
{ Gl6M(<f\5
// output.writeLong(nPos); VBN=xg}
output.writeLong(fileSplitterFetch.nStartPos); 8-s7s!j
output.writeLong(fileSplitterFetch.nEndPos); =M."^X
} 3%(BZ23
output.close(); /=@V5)
} |44 E:pA
catch(IOException e){e.printStackTrace ();} A|`mIma#
catch(Exception e){e.printStackTrace ();} 6 =H]p1p~O
} hRI?>an
=,J-D6J?
>9+h2B
//读取保存的下载信息（文件指针位置） vo"?a~kY7
private void read_nPos() O!k C
{ kKs}E| T
try{ 2u%YRrp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v/GZByco>
int nCount = input.readInt(); 1EHL8@.M
nStartPos = new long[nCount]; 7?p>v34A
nEndPos = new long[nCount]; Vv_lBYV
for(int i=0;i<nStartPos.length;i++) =`OnFdI
{ Ca}V5O
nStartPos = input.readLong(); l_i&8*=Px
nEndPos = input.readLong(); ^US ol/
} s(8e)0Tl
input.close(); [;pL15-}4
} W690N&Wz
catch(IOException e){e.printStackTrace ();} K#kMz#B+i
catch(Exception e){e.printStackTrace ();} _-:CU
} jAxrU
*[+{KJ
XR+
private void processErrorCode(int nErrorCode) zrL+:/t
{ q^eLbivVE
System.err.println("Error Code : " + nErrorCode); U.pGp]\Q)G
} V|vXxWm/
:I(d-,C
k9!euj&
//停止文件下载 t8f:?
public void siteStop() sP@7%p>wt
{ 6FFM-9*|[
bStop = true; ftaa~h*
for(int i=0;i<nStartPos.length;i++) fn, YH
fileSplitterFetch.splitterStop(); 71c(Nw~iQ
6){nu rDBG
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} :NynNu'
} B4eV$~<
//负责部分文件的抓取 M-/2{F[
**FileSplitterFetch.java #]*]qdQWV^
*/ sf Zb$T J
package NetFox; XaH;
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T-y5U},
import java.io.*; srryVqgS
import java.net.*; :U,-v
30bdcDm,
l9z{pZ\KM
public class FileSplitterFetch extends Thread { [8'^"
NL-V",gI-~
z,g\7F[
String sURL; //File URL >rY^Un{Z
long nStartPos; //File Snippet Start Position 3 p!t_y|SX
long nEndPos; //File Snippet End Position jJV1 /]TJ
int nThreadID; //Thread's ID D77s3AyHK
boolean bDownOver = false; //Downing is over "eIE5h
boolean bStop = false; //Stop identical SedVp cb+
FileAccessI fileAccessI = null; //File Access interface +R',$YzD
Rnw v/)
%+oV-o\ #A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =}%Q}aPp
{ kZ'wXtBYe
this.sURL = sURL; S\sy] 1*?$
this.nStartPos = nStart; $msf~M*
this.nEndPos = nEnd; br')%f}m
nThreadID = id; -Yg?@yt
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =kb/4eRg
} BFQ`Ab+
=%d.wH?dZ/
+wcif-
public void run() FKy2C:R(]
{ (!%w
while(nStartPos < nEndPos && !bStop) ]RxWypA`
{ T/?C_i
#c(BBTuX
B:6VD /qC
try{ "DSRyD0M
URL url = new URL(sURL); Yb?(Q%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bd&Nf2
httpConnection.setRequestProperty("User-Agent","NetFox"); NdB:2P
String sProperty = "bytes="+nStartPos+"-"; ,S?M;n?z_
httpConnection.setRequestProperty("RANGE",sProperty); 87rHW@\](
Utility.log(sProperty); |XJ|vQGU
EMf"rGXu(
A5~OHmeK
InputStream input = httpConnection.getInputStream(); nTHCb>,vM
//logResponseHead(httpConnection); ZOy^TR
G|j8iV O
Go !{T
byte[] b = new byte[1024]; `!C5"i8+i2
int nRead; [0H]L{yV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .[o`TlG%
{ BOme`0A
nStartPos += fileAccessI.write(b,0,nRead); ?>q5Abp[
//if(nThreadID == 1) SHQgI<D7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z q@"qnr
} *l)}o4-$
GriFb]ml"
c3N,P<#
Utility.log("Thread " + nThreadID + " is over!"); ~8EzK_c
bDownOver = true; o)M<^b3KO
//nPos = fileAccessI.write (b,0,nRead); ;O {"\H6
} Nuaq{cl
catch(Exception e){e.printStackTrace ();} V82hk0*j
} (/C 8\}Ox
} s'$3bLcb
k<
' BY|7j~
//打印回应的头信息 Tua#~.3}J
public void logResponseHead(HttpURLConnection con) }Io5&ww:U
{ Is>~P*2Y=
for(int i=1;;i++) U,V+qnS
{ *rmM2{6
String header=con.getHeaderFieldKey(i); $spk.j
if(header!=null) Wux[h8G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uE'Kk8
Utility.log(header+" : "+con.getHeaderField(header)); RP%FMb}nt
else *#j_nNM4
break; -EG=}uT['b
} k; ned
} }r|$\ms
`vD.5
Wo~;h(6
public void splitterStop() g1&q6wCg|
{ %(>,eee_
bStop = true; [#;CBs5o
} u_6x{",5I
;Mz7emt
\`-a'u=S
} _z53r+A
ITfz/d8
?cB26Zrcb
/* {=9"WN
**FileAccess.java (1Klj+"p%
*//文件访问(定位，写) dg4q+
package NetFox; r?HbApV P
import java.io.*; GxA[N
QFIYnxY9
Uwg*kJ3H
public class FileAccessI implements Serializable{ &[kFl\
%wN*Hu~E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9S8V`aC
RandomAccessFile oSavedFile; T}K@ykT
long nPos; WntolYd
VTK +aI
/#!1
public FileAccessI() throws IOException -GYJ)f
{ #1Iev7w
this("",0); cN~F32<
} FLLfTkXdI
15M!erT
b ; U
public FileAccessI(String sName,long nPos) throws IOException +Os9}uKf
{ t<MO~_`!
oSavedFile = new RandomAccessFile(sName,"rw"); bCV_jR+
this.nPos = nPos; bOD]`*q
oSavedFile.seek(nPos); W('V2Z-q
} #^xj"}o@
~$m:j];
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public synchronized int write(byte[] b,int nStart,int nLen) ^IO\J{U{"x
{ EC7)M}H
int n = -1; kn}bb*eZ
try{ f s2}a
oSavedFile.write(b,nStart,nLen); VUzRA"DP|
n = nLen; \2M{R
} N$M:&m3^
catch(IOException e) nT=XWM
{ rtz ]PH
e.printStackTrace (); 8@7leAq!
} 83_vo0@<6
,ygDNF
a2B9 .;F
return n; $.3J1DU
} x57O.WdN
S+GW}?!
rAA?{(!9x
} X-`PF
+7r?vo1
1Sd<cOEd
/* pI( H7 (
**SiteInfoBean.java - @tL]]
*/ ;OSEMgB1
package NetFox; TbgIr
J9lG0
VMw[M^
public class SiteInfoBean { fwv.^kx
*|6*jU
x$.0:jP/s
private String sSiteURL; //Site's URL UVgDm&FF
private String sFilePath; //Saved File's Path S0?e/VWy
private String sFileName; //Saved File's Name \ \gAa-}:
private int nSplitter; //Count of Splited Downloading File -d^c!Iu|
o&Y R\BI/
|N:kf&]b
public SiteInfoBean() '}F..w/
{//nSplitter的缺省值为5 A\|:hzu+
//default value of nSplitter is 5 ?~/_&=NSx
this("","","",5); {0L)B{|
} N'YQ6U
L | #"Yn
_C@<*L=Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 90gKGyxF
{ X 1}U
sSiteURL= sURL; aEdc8i?
sFilePath = sPath; LknV47vd
sFileName = sName; eOJ_L]y-
this.nSplitter = nSpiltter; `bW0Va N
)|KZGr
<"nF`'olV
} (>`S{L C>s
]s`cn}d
lhB;jE
public String getSSiteURL() + De-U.
{ 1aoKf F(
return sSiteURL; x/IAc6H~_8
} QT\"r T9#
@^nE^;
]Ryg}DOQ
public void setSSiteURL(String value) n1rJ^q-G
{ U[6 ~ad a
sSiteURL = value; Su*Pd;
} G4G<Ow)`
L6J.^tpO
0xUn#&A~
public String getSFilePath() I?CfdI
{ J/\^3rCB
return sFilePath; ,AG k4]
} T 2Gscey
[>|6qY$D
Zz!yv(e)H
public void setSFilePath(String value) spTIhZ
{ Y.E]U!i*
sFilePath = value; 4q\gFFV4
} 7A{,)Y/w ^
p)s*Cw
\{ff7_mLo
public String getSFileName() CykvTV Q
{ T*](oA@
return sFileName; _7,4C?
} ,{BF`5bn|
S(G&{KG
-"}nm!j /5
public void setSFileName(String value) 2cko GafG{
{ x{1S!A^
sFileName = value; |]]Rp
} 6{H@VF<QY!
MsP`w3b
S&MF; E6
public int getNSplitter() bH.f4-.u>)
{ fn Pej?f:
return nSplitter; M^0^l9w
} i?6#>;f
#fq&yjl#A
m*` W&k[
public void setNSplitter(int nCount) 'v%v*Ujf[
{ ]~\%ANoi
nSplitter = nCount; ef:YYt{|q
} ;:8SN&).
} HA~BXxa/
tfPe-U
4AYW'j C
/* sNsWz.DLT#
**Utility.java :Kk+wp}f#
*/ $pj;CoPm
package NetFox; eV(
Wn5xX5H C
s\q m
public class Utility { q!<n\X3]u
jKp79].
:nxBM#:xu
public Utility() fPab%>/T{
{ yXCJ?
hh<ryuZ
$8fJDN
} ~-#8j3 J;
BZk0B?
//线程睡眠 5KL??ao-
public static void sleep(int nSecond) 7rIEpN>*
{ #F ;@Qi3z
try{ C@rIyBj1g
Thread.sleep(nSecond); ;bkvdn}
} 0"koZd,c
catch(Exception e) InB'Ag"
{ k<k@Tlo
e.printStackTrace (); =S|dzgS/
} l*+9R
} }/aqh;W
Kk6i
//日志 uex([;y
public static void log(String sMsg) 7t|011<
{ sEcg;LFp
System.err.println(sMsg); pZ&?uo67_
} !^qpV7./l
lnt}l
#BhcW"@
public static void log(int sMsg) U] av{}U
{ T;{"lp.
System.err.println(sMsg); G>S3?jGk
} nOq`Cwh9
} 5k`Df/
[*d<LAnuWP
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/* #NQx(C
**TestMethod.java -~&T0dt~
*/ KdLj1T
package NetFox; UI74RP
aa/_:V@$~
]I(<hDuRp
public class TestMethod { aU%QJ#j
$DhW=(YM_a
{@ Z%6%'9
public TestMethod() *&$2us0%%
{ ///xx/weblogic60b2_win.exe k;!}nQ&
try{ Lo5CVlK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k:*vD"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); gi<%: [jT
SiteFileFetch fileFetch = new SiteFileFetch(bean); <Eh_
fileFetch.start(); ;!pJ%p0Sc
} ~o8x3`CoF
catch(Exception e){e.printStackTrace ();} 3(=QY)
jDCf]NvOPM
e6_`
} ]s}9-!{O
K'S\$
r<EwtO+x
public static void main(String[] args) UiH5iZ<r;
{ VVHL@
new TestMethod(); s+6tdBvzs
} 4x?4[J~u[
} 0 1:(QJ
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