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)); mndNkK5o
} ,ce$y4%(
for(int i=0;i<nEndPos.length-1;i++) 7ws[Rp8
{ B/EGaYH
nEndPos = nStartPos[i+1]; {RH)&k&%
} Fz$^CMw5K
nEndPos[nEndPos.length-1] = nFileLength; \D! I"mr
} `]2y=f<{X
} N1]P3
Wc/B_F?2
Dd,]Y}P
//启动子线程 [4}U*\/>C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *_uGzGB&G
for(int i=0;i<nStartPos.length;i++) `$VnB
{ #fF';Y7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hTAZGV(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A6F/w
nStartPos,nEndPos,i); wo) lkovd
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,Ct1)%
fileSplitterFetch.start(); U$IB_a2
} 9\R+g5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4V5h1/JPm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Nu%MXu+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", sTYA
nEndPos = " + nFileLength); <(o) * Zmo
// fileSplitterFetch[nPos.length-1].start(); z`y^o*qc]
yLvU@V@~
/3 ;t &]
//等待子线程结束 S?(/~Vb%
//int count = 0; vQ DlS1L
//是否结束while循环 eq36mIo
boolean breakWhile = false; lLL)S
yKOC1( ~
4{=^J2z
while(!bStop) b U>.Bp]
{ , *Z!Bd8
write_nPos(); <3bFt[
Utility.sleep(500); ca$K)=cDW
breakWhile = true; A!`Q[%$
EYKV}`
RMxFo\TK;
for(int i=0;i<nStartPos.length;i++) K!SFS
{ y$HV;%G{26
if(!fileSplitterFetch.bDownOver) NB)22 %
{ yUFT9bD
breakWhile = false; ,S=ur%
break; Md1ePp]
} a"X9cU[
} BP0*`TY
if(breakWhile) s\ YHT.O?
break; hdH}4W
Eg#WR&Uq"
ksli-Px
//count++; ^/$bd4,z
//if(count>4) kt hy9<!$
// siteStop(); m2PI^?|e
} 10e~Yc
1ihdH1rg[
[-JU(:Rh
System.err.println("文件下载结束！"); zM|Y X<
} sb*)K,U
catch(Exception e){e.printStackTrace ();} =E-V-?N\
} ]9NA3U7F
6n$g73u<=3
Z {*<Gx
//获得文件长度 ?hnxc0~P
public long getFileSize() :PDyc(s{
{ E(Y}*.\]#s
int nFileLength = -1; XlU`jv+
try{ W v!%'IB
URL url = new URL(siteInfoBean.getSSiteURL()); ]*vv=@"`e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4xD`Z_U
httpConnection.setRequestProperty("User-Agent","NetFox"); :5BVVa0oR
QNgfvy
4Yya+[RY
int responseCode=httpConnection.getResponseCode(); 8~8VoU&
if(responseCode>=400) #\$AB_[ot>
{ y^hCO:`l3
processErrorCode(responseCode); p`06%"#
return -2; //-2 represent access is error Lk1e{!a
} v_e3ZA:%
c^EU&q{4
F>s5<pKAX
String sHeader; Fhk`qh'i
qO}Q4a+
9._owKj
for(int i=1;;i++) J'Y;j^
{ !juh}q&}|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <K zEn+
//Utility.log(in.readLine()); ,FDRU
sHeader=httpConnection.getHeaderFieldKey(i); MON]rj7
if(sHeader!=null) *'hJ5{U
{ 6~c:FsZ)
if(sHeader.equals("Content-Length")) :[.**,0R
{ 'yR)z\)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); BDz7$k]
break; x3Ze\N8w
} &-hXk!A
} 7Nt6}${=z
else [e;c)XS[
break; zM2_z
} Q?]-/v
} E8]kd
catch(IOException e){e.printStackTrace ();} k?;B1D8-n
catch(Exception e){e.printStackTrace ();} j NkobJ1
fKOC-%w
gis;)al
Utility.log(nFileLength); GX;~K
^n&_JQIXb
B'8/`0^n5
return nFileLength; 5l4YYwd>v
} I::|d,bR!
]YWz;Z
Dg o-Os@
//保存下载信息（文件指针位置） TNkvdE-S
private void write_nPos() fuF!3Q
{ 3 G_0DS
try{ 6w)a.^yx7
output = new DataOutputStream(new FileOutputStream(tmpFile)); jWqjGX`
output.writeInt(nStartPos.length); \x;`8H
for(int i=0;i<nStartPos.length;i++) Bw25+l Px
{ ="J *v>
// output.writeLong(nPos); YML]pNB
output.writeLong(fileSplitterFetch.nStartPos); bfXyuv
output.writeLong(fileSplitterFetch.nEndPos); L(+I
} U;#9^<^
output.close(); T1#r>3c\
} :kQydCuK
catch(IOException e){e.printStackTrace ();} Bvsxn5z+:
catch(Exception e){e.printStackTrace ();} _T\cJcWf
} )J{.z
|Q+:vb:
'|^x[8^
//读取保存的下载信息（文件指针位置） BnUWg ^E
private void read_nPos() W!t=9i
{ ble[@VW|
try{ WJj5dqatV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R,dbq4xkl
int nCount = input.readInt(); 9wbj}tN\z
nStartPos = new long[nCount]; TQ5*z,CkS
nEndPos = new long[nCount]; ,8G6q_ud
for(int i=0;i<nStartPos.length;i++) T7~H|%
{ @L?KcGD
nStartPos = input.readLong(); 7BkY0_KK
nEndPos = input.readLong(); RG_.0'5=hc
} B-UsMO
input.close(); .C,D;T{
} `Vl9/IEk
catch(IOException e){e.printStackTrace ();} YJu~iQ`i
catch(Exception e){e.printStackTrace ();} {;vLM* '
} 03H0(ku=
y4)iL?!J~
M>[e1y>7
private void processErrorCode(int nErrorCode) z"P/Geb:O
{ `3yK<-
System.err.println("Error Code : " + nErrorCode); Z@,[a
} d$hBgJe>N
Q|xa:`3?
*}) W>
//停止文件下载 7!Qu+R
public void siteStop() Z0%:j\W4c
{ 4i7+'F
bStop = true; 49.B!DqQW&
for(int i=0;i<nStartPos.length;i++) 5Mz:$5Tm
fileSplitterFetch.splitterStop(); 1]69S(
Kf1NMin7
+\]Gu(z<
} }Xvm( ;
} 8PR\a!"
//负责部分文件的抓取 L3=5tuQ[5
**FileSplitterFetch.java Qk72ra)
*/ +/ rt'0o
package NetFox; C),i#v
Z+=M_{`{
1Li*n6tLX`
import java.io.*; slzB#
import java.net.*; y9b%P]i
<*(^QOM
l];/,J^
public class FileSplitterFetch extends Thread { 6n^@Ps
RdBIbm
"+E\os72|
String sURL; //File URL Y>6N2&Q
long nStartPos; //File Snippet Start Position )2a)$qx;
long nEndPos; //File Snippet End Position ]I_*+^?tI
int nThreadID; //Thread's ID aW-6$=W
boolean bDownOver = false; //Downing is over Wdi`ZE
boolean bStop = false; //Stop identical 0SDnMij&bf
FileAccessI fileAccessI = null; //File Access interface #%EHcgF
4Cv*zn
(x fN=Te,-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ``%yVVg}
{ -9::M}^2
this.sURL = sURL; k%BU&%?1
this.nStartPos = nStart; .,20_<j%=
this.nEndPos = nEnd; #q4uS~
nThreadID = id; df!i}L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^t:dcY7
} 2RQ-L
PV:J>!]
>n^780S|
public void run() T*nP-b
{ jD${ZIv
while(nStartPos < nEndPos && !bStop) SA7(EJ95
{ Re&"Q8I.8
[Q+k2J_h
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try{ G[1\5dK*uR
URL url = new URL(sURL); ?}uuTNLl)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h aApw(.%
httpConnection.setRequestProperty("User-Agent","NetFox"); L&s$&E%
String sProperty = "bytes="+nStartPos+"-"; Uo71C4ev
httpConnection.setRequestProperty("RANGE",sProperty); `BVmuUMm
Utility.log(sProperty); ]f0OmUHR5i
1 +[sM
T7%!JBg@
InputStream input = httpConnection.getInputStream(); L$BV`JWPw
//logResponseHead(httpConnection); "Kdn`zN{
G;$;$gM
'qvj[lpGr
byte[] b = new byte[1024]; K|YB)y
int nRead; aCI3Tx&2qT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) K{{_qFj@<y
{ zCuB+r=C
nStartPos += fileAccessI.write(b,0,nRead); `CI_zc=jx
//if(nThreadID == 1) 2;u i'B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aydNSgu
} ^H&U_
> K?OsvX
k%FA:ms|k
Utility.log("Thread " + nThreadID + " is over!"); rlD!%gG2x
bDownOver = true; n}j6gN!O
//nPos = fileAccessI.write (b,0,nRead); 15hqoo9!
} Fj(GyPFG
catch(Exception e){e.printStackTrace ();} /0 4US5En
} P:t .Nr"
} a eeor
MM_:2 ^P)
+D:8r|evH
//打印回应的头信息 -rn6ZSD)
public void logResponseHead(HttpURLConnection con) vaGF(hfTA
{ N@L{9ak1
for(int i=1;;i++) e"52'zAV-
{ ~7U~
String header=con.getHeaderFieldKey(i); r4fHD~#l{
if(header!=null) c(e>Rmh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p |1u,N
Utility.log(header+" : "+con.getHeaderField(header)); ,|B-Nq
else t`&x.o
break; 8'HS$J;C
} {eV8h}KIl
} `/ayg:WSU
P/girce0
hd u2?v@
public void splitterStop() 8M@'A5]
{ [d8Q AO1;)
bStop = true; RGE(#
} c#sHnpP
YT Zi[/
o]Rlivahm
} qQi\/~Y[:
4]uj+J
eM:J_>7t
/* Iz5NA0[=2
**FileAccess.java _BmObXOp.
*//文件访问(定位，写) Ph1XI&us9
package NetFox; =i&,I{3
import java.io.*; z.!N|"4yr
L_NiU;cr%
%^pi
public class FileAccessI implements Serializable{ m&Mupl
+ti ?7|bK<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `(sb
RandomAccessFile oSavedFile; R<Lf>p>_
long nPos; `daqzn
iU;e!\A
AQg|lKv
public FileAccessI() throws IOException akxNT_
{ Y8\P"qb
this("",0); /,I cs
} .mt%8GM
|zYOCDFf
o)/Pr7Qn
public FileAccessI(String sName,long nPos) throws IOException 4=xi)qF/@
{ /.Ak'Vmi
oSavedFile = new RandomAccessFile(sName,"rw"); %,kP_[!>Q
this.nPos = nPos; >H!Mx_fDL
oSavedFile.seek(nPos); 15\m.Ix
} ^AS\a4`/
6!ve6ZB[p
hTr5Q33y>
public synchronized int write(byte[] b,int nStart,int nLen) lUm(iYv;H
{ VN0We<\Z
int n = -1; CwA_jOp
try{ ViPC Yt`of
oSavedFile.write(b,nStart,nLen); X#lNS+&='
n = nLen; (~=.[Y
} En?V\|,
catch(IOException e) //U1mDFT
{ ?)xIn)#ls
e.printStackTrace (); h_vTA
} lmvp,BzC
h'):/}JPl
2Wz8E2.
return n; _\}'5nmw\
} d,V#5l-6
,Of^xER`
O1J&Lwpk,
} &12KpEyf
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sjr,)|#[
/* ,50
**SiteInfoBean.java !Rn6x $_
*/ &9p!J(C
package NetFox; Z<-_Y]4j
%9J@##+
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public class SiteInfoBean { nqcq3o*B
W)In.?>]W
Ke\\B o,
private String sSiteURL; //Site's URL HTJ2D@h
private String sFilePath; //Saved File's Path I,j4 BU4
private String sFileName; //Saved File's Name Tlsh[@Q
private int nSplitter; //Count of Splited Downloading File /kW Z 8Z
mgq!)
_FY&XL=
public SiteInfoBean() Fb5U@X/vE
{//nSplitter的缺省值为5 jT{T#_
//default value of nSplitter is 5 sgX!4wG&Z
this("","","",5); GXtMX ha,
} jFj11w1FrA
OSgJj MQ
)'_[R@ThB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b(H{i}{]
{ /4:bx#;A
sSiteURL= sURL; 1i76u!{U
sFilePath = sPath; _ E;T"SC
sFileName = sName; Zv u6/#
this.nSplitter = nSpiltter; 9DxHdpOk
`8:)? 0Ez
zfIo]M`
} yn4T!r "
xM*_1+<dT$
-@W9+Zf5
public String getSSiteURL() ,fkvvM{mq
{ Td=4V,BN
return sSiteURL; 8\n3 i"
} nw+~:c
Xn6#q3;^|
A6N6e\*
public void setSSiteURL(String value) QU"WpkO
{ -+#%]P8l
sSiteURL = value; f%Q{}fC{*
} aF{_"X2
X'Ss#s>g
<$~lFV
public String getSFilePath() [{znwK@
{ ;[v!#+yml
return sFilePath; R'Sd'pSDN
} h)KHc/S
jEc_!Q
YG "Ta|@5
public void setSFilePath(String value) L:R4&|E/t
{ {f/qI`
sFilePath = value; f-ltV<C_
} 3[YG BM(
v, $r.g;
t un}rdb
public String getSFileName() Ot=jwvw
{ #@XBHJD\#
return sFileName; dGIdSQ~ _
} d+9V% T
]ss[n.T0*
zA,vp^
public void setSFileName(String value) CWj_K2=d
{ D tsZP (
sFileName = value; 7=G2sOC
} S$6|KY u
Njq}M/{U
U&!TA(Yr
public int getNSplitter() j#NyNv(jE1
{ @CMI$}!{V
return nSplitter; 615Ya<3f8
} ,6)N.
ks405
wj)LOA0
public void setNSplitter(int nCount) vB:\ZX4
{ Y"Cf84E
nSplitter = nCount; @=-(H<0
} P"YdB|I
} YW}$eW*
x.SfB[SZ
i'>6Qo
/* BZq#OAp
**Utility.java '\:4Ijp<"
*/ -t`kb*O3`
package NetFox; ?w3RqF@}
=%Y1]F
YagfCi ?
public class Utility { OgQdyU
]?9*Vr:P^
nL@'??I1
public Utility() mypV[
{ sS D8Sx/
AjzTszByu
-<W?it?D
} c4JV~VS+
j-<]OOD
//线程睡眠 j3j?2#vR
public static void sleep(int nSecond) 2g.lb&3W
{ _&<n'fK[
try{ 5mH[|_
Thread.sleep(nSecond); _^NX`<&
} > p`,
catch(Exception e) .<x6U*)\O
{ ~Y 6'sM|
e.printStackTrace (); u4x-GObJM
} L2}\Ah"[
} /6x&%G:m#
8 Rx@_
//日志 l|CM/(99-
public static void log(String sMsg) _NDQ2O
{ OO:S2-]Y>e
System.err.println(sMsg); uLhGp@Dx
} Od1\$\4Z
Sj+H{xJi
g4K+AK
public static void log(int sMsg) 'aSsyD!?<
{ ,jU>V]YC
System.err.println(sMsg); GQ2GcX(E(
} aZ#FKp^8H
} rRTKF0+
|IgR1kp+.
Xp<q`w0I,
/* *x36;6~W;
**TestMethod.java Llfl I
*/ \)PB p
package NetFox; v{u3[c
Z8v\>@?5R
c&['T+X
public class TestMethod { c_/BS n
ot0teNF
hkK>h
public TestMethod() ddn IKkOp
{ ///xx/weblogic60b2_win.exe u Ie^Me
try{ 7?.uAiM'zT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H2X_WSwm
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); eG=d)`.JaV
SiteFileFetch fileFetch = new SiteFileFetch(bean); P,v7twc0M
fileFetch.start(); r!r08yf
} xfk -Ezv
catch(Exception e){e.printStackTrace ();} #S>N}<>
lhUGo =
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} Gu;40)gm
$LP(\T([
_i=*0Q
public static void main(String[] args) Z{8%Cln
{ RdCGK?s
new TestMethod(); wL;OQhI
} cVi_#9u"
} ~OD6K`s3
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