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)); N,ik&NIWy
} 'w%N(Ntq
for(int i=0;i<nEndPos.length-1;i++) JMOP/]%D
{ 7/vr!tbL`p
nEndPos = nStartPos[i+1]; {I 7pk6Qd
} P:k(=CzZ@J
nEndPos[nEndPos.length-1] = nFileLength; wc%
} {NK>9phoB
} ;_i0@@J
Jb-wvNJu
x=B+FIJ
//启动子线程 =] 5;=>(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <nsl`C~6g0
for(int i=0;i<nStartPos.length;i++) l1cBY{3QD
{ LbR/it'}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eq/5$b(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [Pp#l*
nStartPos,nEndPos,i); !E_uQ?/w]Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z K8#gif@
fileSplitterFetch.start(); ~DZ;l/&Mz7
} LO61J_J<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YLd 5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d L%E0o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i`]M2Q
nEndPos = " + nFileLength); ,:\2Lf
// fileSplitterFetch[nPos.length-1].start(); f9- |!]s
;oFaDTX]
hqD;<:.
//等待子线程结束 lO $M6l
//int count = 0; 0]oQ08
//是否结束while循环 SA>;]6)`(
boolean breakWhile = false; .%wEuqW=0
)Qxv9:X
E2*"~gL^,
while(!bStop) ,.`^Wx6F
{ 6 qKIz{;
write_nPos(); !v;r3*#Nky
Utility.sleep(500); J#V`W&\,6
breakWhile = true; w78Ius,
lIjHd#q-C
cHsJQU*K6
for(int i=0;i<nStartPos.length;i++) h/TPd]
{ Bh' vr3|
if(!fileSplitterFetch.bDownOver) , D1[}Lr=K
{ aJ)5DlfLR
breakWhile = false; V2FE|+R%g
break; M<$l&%<`G
} ` `;$Kr
} ')1sw%[2
if(breakWhile) peqFa._W
break; H9)uni
''v1Pv-
d7^XP
//count++; 8e\v5K9
//if(count>4) _&%!4n#>
// siteStop(); e4)gF*
} sId5pY!
aq5<Ks`r
E7eVg*Cvi
System.err.println("文件下载结束！"); ygfqP
} &HXSO,@
catch(Exception e){e.printStackTrace ();} FY|x<-f
} hE6tu'
ewY[vbF
\7j)^
//获得文件长度 *i?qOv/=>
public long getFileSize() `X^e}EGWu
{ YqJIp. Z
int nFileLength = -1; ^w12k2a
try{ fcZOsTj
URL url = new URL(siteInfoBean.getSSiteURL()); Mc}x]j`f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t!u*6W|@
httpConnection.setRequestProperty("User-Agent","NetFox"); S-/#3
Ys_YjlMIbl
Y+jKP*ri
int responseCode=httpConnection.getResponseCode(); -mkync3
if(responseCode>=400) bp$jD
{ JZXc1R| 9
processErrorCode(responseCode); Ksp;bfe
return -2; //-2 represent access is error " }ZD)7K
} .E}});l
aXJe"IT.u
Y@4vQm+
String sHeader; rka:.#!
UA8!?r-cR
h@DJ/&;u@
for(int i=1;;i++) ;p_X7N
{ !xc7~D@om(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y^A$bTQq
//Utility.log(in.readLine()); ;Pa(nUE@
sHeader=httpConnection.getHeaderFieldKey(i); *=7[Ip<X
if(sHeader!=null) ~/x42|t
{ /< :;^B
if(sHeader.equals("Content-Length")) "QF083$
{ ;dFe >`~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VxFy[rP
break; @ubz?5
} \fz j fZ1n
} Yq^y"rw
else Zb}PP;O
break; g7P1]CZ}
} <di_2hN
} i`SF<)M(
catch(IOException e){e.printStackTrace ();} w?tKL0c
catch(Exception e){e.printStackTrace ();} \+uqP:Ty
X2uX+}h*tA
EC~t'v
Utility.log(nFileLength); ;9PM?Iy[
R,\ r{@yrz
0c5_L6_z
return nFileLength; V3oAZ34)
} 1 ~7_!
C#~MR+;
`aUp&8{
//保存下载信息（文件指针位置） @,MdvR+a
private void write_nPos() /(V=Um^0
{ qj6`nbZ{va
try{ t4IJ%#22
output = new DataOutputStream(new FileOutputStream(tmpFile)); =vc5,
output.writeInt(nStartPos.length); Rpk`fxAO
for(int i=0;i<nStartPos.length;i++) `"H?nf0
{ Ds87#/Yfv
// output.writeLong(nPos); rxK0<pWJhx
output.writeLong(fileSplitterFetch.nStartPos); (OqJet2{+
output.writeLong(fileSplitterFetch.nEndPos); QC4T=E]`j
} [j?<9
output.close(); gHx-m2N
} HUC2RM?FN
catch(IOException e){e.printStackTrace ();} +I<Sq_-
catch(Exception e){e.printStackTrace ();} T,uIA]
} V)2_T!e%*
W\,lII0
z\tJ~
//读取保存的下载信息（文件指针位置） B0i}Y-Z
private void read_nPos() T]|O/
{ gn"&/M9E
try{ OQ7c|O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 'u[o`31.
int nCount = input.readInt(); sPg6eAd~?
nStartPos = new long[nCount]; k^pu1g=6I
nEndPos = new long[nCount]; >p*HXr|o$
for(int i=0;i<nStartPos.length;i++) j>*SJtq7
{ $Jm2,Yv
nStartPos = input.readLong(); hPxI& :N
nEndPos = input.readLong(); `&_k\/
} ge?-^s4M
input.close(); <~M9nz(<
} V@:=}*E
catch(IOException e){e.printStackTrace ();} ^qqHq
catch(Exception e){e.printStackTrace ();} ?Q)Z..7
} winJ@IYW
C/waH[Yzan
A{2$hKqHi
private void processErrorCode(int nErrorCode) RuNH (>Eb
{ d;SRK @
System.err.println("Error Code : " + nErrorCode); %-/:ps
} t4/eB<fP
5"am>$rh
-C ON
//停止文件下载 G=cH61
public void siteStop() )6E*Qz
{ A9UaLSe
bStop = true; !>y}Xq{bm3
for(int i=0;i<nStartPos.length;i++) )_e"Nd4
fileSplitterFetch.splitterStop(); `^-Be
TDIOK
[7 `Dgnmq
} tgtoK|.
} FRt/{(jro
//负责部分文件的抓取 ,?<h] !aQ
**FileSplitterFetch.java m]d6@"Z.
*/ ^Cn]+0G#C8
package NetFox; Kw0V4UF
0~b6wuFl
!7`=rT&
import java.io.*; pE/3-0;}N
import java.net.*; d4>-a^)V
1IQOl
rg^\BUa-W,
public class FileSplitterFetch extends Thread { z%3"d0
= )l:^+q
q>(u>z!
String sURL; //File URL ;9p5YxD
long nStartPos; //File Snippet Start Position `$Flgp0P
long nEndPos; //File Snippet End Position [RFK-E
int nThreadID; //Thread's ID $t# ,'M
boolean bDownOver = false; //Downing is over }0*ra37z>
boolean bStop = false; //Stop identical ]a!; `m$
FileAccessI fileAccessI = null; //File Access interface Z*(!`,.bB
06 Esc^D
&tz%WW%D8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /Np"J
{ tD7C7m
this.sURL = sURL; 8^/Ek<Qb|
this.nStartPos = nStart; O;BMwg_7
this.nEndPos = nEnd; B Ff.Rd95
nThreadID = id; oB06{/6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0/P-> n~
} mz$Wo *FB
=R;1vUio
vYR=TN=Z4
public void run() ,cy/fW
{ _Kl{50}]
while(nStartPos < nEndPos && !bStop) QjjJtKz
{ y~c4:*L3
$ lsRg:J
.V 3X#t
try{ PP[)h,ZL*
URL url = new URL(sURL); {iIg 4PzrU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7! b)'W?
httpConnection.setRequestProperty("User-Agent","NetFox"); $F@L$&~
String sProperty = "bytes="+nStartPos+"-"; B,vHn2W
httpConnection.setRequestProperty("RANGE",sProperty); JNM@Q
Utility.log(sProperty); 76_8e{zbr
}RN=9J
,gL)~6!A
InputStream input = httpConnection.getInputStream(); N 1f~K.e\
//logResponseHead(httpConnection); W3{<e"
iWN.3|r
$:u7Dv}\
byte[] b = new byte[1024]; E0)mI)RW.
int nRead; ),p]n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f-v ND'@
{ @t;O"q'|
nStartPos += fileAccessI.write(b,0,nRead); ?9zoQ[
//if(nThreadID == 1) ~?`9i>3W~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z^!A/a[[!
} j&[3Be'pQ
J'&B:PZObB
??zABV
Utility.log("Thread " + nThreadID + " is over!"); )-9w3W1r
bDownOver = true; Pvg
//nPos = fileAccessI.write (b,0,nRead); Ro'4/{}+
} ^I'Lw
catch(Exception e){e.printStackTrace ();} !w#ru?L{
} ;sck+FP7w
} uU[[[LQq
z@%/r~?|
^=izqh5S
//打印回应的头信息 }lC64;yo
public void logResponseHead(HttpURLConnection con) f}lT|.)?VD
{ 7<QYT+6xV
for(int i=1;;i++) U8WHE=Kk\h
{ qD$GKN.
String header=con.getHeaderFieldKey(i); t.>te'DK/
if(header!=null) n$m]58w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {*<O"|v
Utility.log(header+" : "+con.getHeaderField(header)); @wB'3q}(
else d)hzi
break; 6Y>,e;R
} y\|-O<8O
} lNA'M&
3<jAp#bE
1fO2)$Y
public void splitterStop() fUp|3bBE
{ }/7.+yD
bStop = true; mHI4wS>()+
} D?\"
k67i`f=
XMeL^|D
} /]k ,,&
*2"bG1`
gf3u0' $
/* <(#xOe
**FileAccess.java N'eQ>2>O@
*//文件访问(定位，写) 2sd ) w
package NetFox; s.p1L
import java.io.*; EvSnZB1 y
j h1bn
W>q*.9}Y"
public class FileAccessI implements Serializable{ i)@U.-*5m
<@U.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \N`fWh8&
RandomAccessFile oSavedFile; U!a!|s>
long nPos; [U%ym{be^
Yhc6P%{Z^
M!&_qj&N,
public FileAccessI() throws IOException HIPcZ!p
{ IFC%%It5,
this("",0); 0.J1!RIK/
} {FV,j.D
vB{;N
VVI8)h8
public FileAccessI(String sName,long nPos) throws IOException fW5"4,
{ !7mvyc!'!
oSavedFile = new RandomAccessFile(sName,"rw"); k\+y4F8$x
this.nPos = nPos; u@=+#q~/P
oSavedFile.seek(nPos); _XY`UZ
} =9;[C:p0-
XI@6a9Uk
`x%U
public synchronized int write(byte[] b,int nStart,int nLen) 5T$9'5V7
{ 0\\ueMj
int n = -1; )){PBT}t]
try{ Tsm)&$JI8
oSavedFile.write(b,nStart,nLen); [|:QE~U@
n = nLen; ~8H&m,{j
} m0xJ05Zx
catch(IOException e) >G-8FL
{ mHK@(D7X
e.printStackTrace (); #/n|@z'
} cS"f
iXUWIgr
^f^-.X
return n; KAj"p9hq+k
} pY{; Yn&t
iwG>]:K3
3iu!6lC
} L\/u}]dPQ
SWNU1x{,c\
Fe_::NVvk
/* jgo e^f
**SiteInfoBean.java 6)=](VmNL`
*/ ffmG~$Yh_
package NetFox; 8N=%X-R%
ONjC(7
rmY,v
public class SiteInfoBean { ]Y_{P~ZX
\GijNn9ah
-:)DX++
private String sSiteURL; //Site's URL Nk lz_]
private String sFilePath; //Saved File's Path n~1tm
private String sFileName; //Saved File's Name (l\a'3a.
private int nSplitter; //Count of Splited Downloading File Nd]0ta
B,~f "
jGO9n
public SiteInfoBean() )LkM,T
{//nSplitter的缺省值为5 8fJR{jD(s
//default value of nSplitter is 5 :[y]p7;{f
this("","","",5); Y5nz?a
} !7A"vTs
3c01uObTL
.o-0aBG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *0=fT}&!
{ T6sr/<#<(
sSiteURL= sURL; XHWh'G9
sFilePath = sPath; x1|Da$2
sFileName = sName; +\+Uz!YS
this.nSplitter = nSpiltter; 7ZS>1
^c/mj9M#C
sFbfFUd
} gJ]Cq/gC
"sFW~Y
^36M0h|R
public String getSSiteURL() ]WTf< W<
{ v*&Uk'4E
return sSiteURL; Lf5%M|o.)
} K5P Gi#
/)sDnJ1r
CkRyzF
public void setSSiteURL(String value) mG0L !5
{ `-~`<#E[
sSiteURL = value; v2IEJ
} 5iP8D<;o5
K|`+C1!
VMaS;)0f@
public String getSFilePath() (F/HU"C
{ 6_W<hevI
return sFilePath; ^Y$QR]
} pI &o?n
Bk&-1>cY
Xwn3+tSIa
public void setSFilePath(String value) !A~d[</]m
{ F;pTXt}?5
sFilePath = value; yPSVwe|g
} ^gd<lo g
Po1hq2-U8
wHA/b.jH
public String getSFileName() <#zwKTmK1
{ XFtOmY
return sFileName; OWqrD@
} -UJ?L
3voW
q5%2WM]6
public void setSFileName(String value) Q6u{@$(/N
{ a[q84[OQ
sFileName = value; X2i*iW<
} YdK_.t0Mu
T0;u+$
FX7M4t#<
public int getNSplitter() >J.Qm0TY(
{ {nTG~d
return nSplitter; ]y.Rg{iv
} VF\{ra;
l`DtiJ?$$0
Y=9qJ`q
public void setNSplitter(int nCount) F@<O;b#Ip
{ 9e]'OKL+
nSplitter = nCount; Jth=.9mrM
} hBjVe?{
} i^R{Ul[
vT%qILTrQf
;8BA~,4l
/* ~xw5\Y^
**Utility.java 4b]_ #7Qm
*/ F#B5sLNb
package NetFox; sA3UeTf
k'g$2
^/k,
public class Utility { =9^Q"t4
p+RAtRf
>'N!dM.+9
public Utility() Z{} n8b*
{ 8qN"3 Et
V>B'+b+<
m*`cuSU|o
} 4\\.n
i=-8@
//线程睡眠 eI0F!Yon
public static void sleep(int nSecond) MO-!TZ+6
{ _AprkI_
try{ mGO>""<:
Thread.sleep(nSecond); `YU=~xQ
} xHHV=M2l(s
catch(Exception e) &-=K:;x
{ "NKf0F
e.printStackTrace (); U~wjR"='
} JIMWMk;ot
} o*-9J2V=J
-3` "E%9
//日志 La9r
public static void log(String sMsg) a&C.=
{ 7lwTZ*rnY
System.err.println(sMsg); M'DWu|dIBA
} sXiv,
* MEe,4
9s(i`RTM
public static void log(int sMsg) [A]Ca$':
{ JD ]OIh
System.err.println(sMsg); %J _ymJ'pd
} i|S:s
} p0Gk j-
+RS$5NLH
5KJ%]B(H2
/* 5/ * >v
**TestMethod.java VRF6g|0;
*/ t7bqk!6hM\
package NetFox; SRItE\"Xe
ei|cD[ NY
rGQ5l1</
public class TestMethod { @;;G88=
)&,K94
doM?8C#`
public TestMethod() \Tyf*:_F>
{ ///xx/weblogic60b2_win.exe Ig9d#c
try{ g_vm&~U/'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); GD&htob(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v,jhE9_O0
SiteFileFetch fileFetch = new SiteFileFetch(bean); =U"dPLax
fileFetch.start(); f`?0WJ(M
} #uKWuGz]
catch(Exception e){e.printStackTrace ();} B6MkF"J<
M&f#wQ
RLHYw@-j@
} ybE[B}pOeZ
bAiJn<
s"coQ!e1.
public static void main(String[] args) \(fq8AL?
{ Xu#:Fe}:
new TestMethod(); Xpl?g=B&u
} 88l,&2q
} nP1GW6Pu
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