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)); PRal>s&f
} %p;;aZG
for(int i=0;i<nEndPos.length-1;i++) (&i c3/-
{ ]WYddiF
nEndPos = nStartPos[i+1]; J.(mg D
} <s=i5t My5
nEndPos[nEndPos.length-1] = nFileLength; DFMf"_p
} %w#z
} H-iCaXT
{zIcEN$ ~
0e +Qn&$#4
//启动子线程 y9Pw'4R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k 1lK`p
for(int i=0;i<nStartPos.length;i++) a9_KoOa.H
{ 1lYQR`Uh
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L[voouaqm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M 4E|^p=5
nStartPos,nEndPos,i); De ([fC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }ijFvIHV
fileSplitterFetch.start(); rL,kDSLs
} )mH(Hx
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yZ-Ql11
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >H5_,A}f
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }SFmv},Ij
nEndPos = " + nFileLength); :#OaE,
// fileSplitterFetch[nPos.length-1].start(); 9K>~9Za
,7Dm p7
5cj&D74o
//等待子线程结束 O/.8;.d;4Y
//int count = 0; 0nPg`@e.
//是否结束while循环 Ca["tks
boolean breakWhile = false; .npD<*
>r>pM(h
c?*x2Vk
while(!bStop) cwE?+vB
{ [(; .D
write_nPos(); %O9P|04]3
Utility.sleep(500); gI/SA
breakWhile = true; "^)$MAZ
*7{{z%5Pu
hAJ^(|
for(int i=0;i<nStartPos.length;i++) *SYuq)
{ 4N)45@jk[
if(!fileSplitterFetch.bDownOver) F?Fxm*Wa/
{ 5Mp$u756
breakWhile = false; 06 an(&a9
break; W[LQ$uj
} p^C$(}Yh
} [dy0aR$>d
if(breakWhile) G;e)K\[J
break; 19bqz )
by$S#ef
qFp]jbU
//count++; GPrq(
//if(count>4) E~S~Ld%
// siteStop(); 2;7n0LOs}
} =)f.Yf|A*
zG7y$\A
swg*fhJFB
System.err.println("文件下载结束！"); MSb0J`
} je74As[
catch(Exception e){e.printStackTrace ();} F6ZL{2$k@
} IK,aA;d
/tJ%gF
* Na8w'Q
//获得文件长度 F!RP *
public long getFileSize() {>d\
{ >CYz6G j
int nFileLength = -1; Hv*+HUc(:
try{ _4LDzVjNRe
URL url = new URL(siteInfoBean.getSSiteURL()); ?]\v%[ho
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n[7=
httpConnection.setRequestProperty("User-Agent","NetFox"); @`nU=kY/
z>HM$n`YD
^qtJcMK+hq
int responseCode=httpConnection.getResponseCode(); [M?&JA_$}
if(responseCode>=400) 'DUYf5nF
{ +hIMfhF
processErrorCode(responseCode); 7-}/{o*,5
return -2; //-2 represent access is error NkxW*w%}l
} ;Ouu+#s
loD:4e1
Me-H'Mp~
String sHeader; W . dm1
>Ft:&N9L{
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for(int i=1;;i++) >L^2Z*
{ -l<[CI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FXbalQ?^
//Utility.log(in.readLine()); QaLVIsnfN
sHeader=httpConnection.getHeaderFieldKey(i); |iVw7M:
if(sHeader!=null) {;={abj
{ 85{@&T
if(sHeader.equals("Content-Length")) V7?Pv Q
{ Vah.tOU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Zzv,p
break; N#^o,/
} 1ifPc5j}
} ?dvcmXR
else S^)xioKsJ
break; \; zix(N[5
} `llSHsIkXb
} !I Byv%m&\
catch(IOException e){e.printStackTrace ();} cKt8e^P
catch(Exception e){e.printStackTrace ();} 4K!@9+Mz
cC$E"m
`IK3e9QpcA
Utility.log(nFileLength); R-5e9vyS
/&RS+By(i
9]|G-cyt
return nFileLength; Tl*FK?)MC^
} ;CA7\&L>
nn/_>%Y
gX]'RBTb
//保存下载信息（文件指针位置） Lu~M=Fh
private void write_nPos() SA.,Q~_T7
{ G=>LW1E|
try{ h|.*V$3
output = new DataOutputStream(new FileOutputStream(tmpFile)); =mh)b]].4\
output.writeInt(nStartPos.length); 6}q# c
for(int i=0;i<nStartPos.length;i++) $1myf Z
{ ^qPS&G
// output.writeLong(nPos); Ok_)C+o
output.writeLong(fileSplitterFetch.nStartPos); #zKF/H|_R
output.writeLong(fileSplitterFetch.nEndPos); -;U3$[T,J7
} XD|vB+j\O
output.close(); lR3JyYY{X
} J,^eq@(
catch(IOException e){e.printStackTrace ();} 6n'XRfQp)&
catch(Exception e){e.printStackTrace ();} vLh,dzuo
} D4ud|$s1
!\_li+
1 =9 Kwd
//读取保存的下载信息（文件指针位置） d=:&tOCg2
private void read_nPos() OEs!H]v
{ g}'(V>(
try{ l}mzCIw%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N2`u ]*"0
int nCount = input.readInt(); J/^|Y6
nStartPos = new long[nCount]; b{lkl?@a
nEndPos = new long[nCount]; u9)<i]2
for(int i=0;i<nStartPos.length;i++) <utD&D8w
{ +X7+:QQ}
nStartPos = input.readLong(); T\o!^|8
nEndPos = input.readLong(); YGr^uTQb
} uM9RlI5
input.close(); u6BLhyS
} {;ur~KE
catch(IOException e){e.printStackTrace ();} X&({`Uw<K
catch(Exception e){e.printStackTrace ();} 06vxsT@
} }5sJd>u5^
UP |#WegO
9-N*Jhg
private void processErrorCode(int nErrorCode) yX;v
{ s~Od(,K
System.err.println("Error Code : " + nErrorCode); zmh3 Qa(
} U)grC8 C
*dm?,~f%<
C6(WnO{6
//停止文件下载 (eJYv: ^
public void siteStop() -4'yC_8t
{ KRh95B GU
bStop = true; pZe:U;bb
for(int i=0;i<nStartPos.length;i++) zq&,KZ
fileSplitterFetch.splitterStop(); xt"GO b
do(komP<\
\~bE|jWbj
} /=2
} Qd$!?h
//负责部分文件的抓取 j{u!/FD
**FileSplitterFetch.java rocG;$[
*/ zE\@x+k.
package NetFox; . ;q4<_
?$LKn2C
|lhVk\X
import java.io.*; SmYY){AQ/
import java.net.*; ce\ F~8y
\Q<Ur&J]%
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public class FileSplitterFetch extends Thread { , *A',
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String sURL; //File URL 7I_lTu(
long nStartPos; //File Snippet Start Position Y l1sAf/
long nEndPos; //File Snippet End Position RxVf:h'l
int nThreadID; //Thread's ID vS|uN(a.P
boolean bDownOver = false; //Downing is over `*=Tf
boolean bStop = false; //Stop identical ZNvnVW<
FileAccessI fileAccessI = null; //File Access interface -] .Y";
`+/xA\X]
` 'y[i
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -5 YvtL
{ $}G03G@
this.sURL = sURL; }{Ncww!iN
this.nStartPos = nStart; HrZ\=1RB
this.nEndPos = nEnd; #}rv)
nThreadID = id; Q@-7{3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c~+;P(>
} U,4:yc,)s
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public void run() EK6fd#J?1
{ :}Tw+S5
while(nStartPos < nEndPos && !bStop) d= -/'_'
{ $6XCHVx
{D jz']
d M&BnI
try{ t<6`?\Gk
URL url = new URL(sURL); {IW pI *
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @]H:=Q'gj
httpConnection.setRequestProperty("User-Agent","NetFox"); gB\KD{E
String sProperty = "bytes="+nStartPos+"-"; yjbqby7
httpConnection.setRequestProperty("RANGE",sProperty); /v1Rn*VF!
Utility.log(sProperty); 6NV- &0 _
P#g"c.?;
^p0BeSRiy;
InputStream input = httpConnection.getInputStream(); iraO/KhD*3
//logResponseHead(httpConnection); q.OkZI0n
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FSqS]6b3
byte[] b = new byte[1024]; .`OdnLGy
int nRead; I =t{ u;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9@-^!DBM
{ |"Js iT
nStartPos += fileAccessI.write(b,0,nRead); + (cTzY
//if(nThreadID == 1) -VESe}c:nQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~(xIG
} s|U?{Byb!
Mlp[xk|
'[fo
Utility.log("Thread " + nThreadID + " is over!"); VR>;{>~
bDownOver = true; fL8+J]6A6
//nPos = fileAccessI.write (b,0,nRead); p*rBT,'
} pNo<:p
catch(Exception e){e.printStackTrace ();} AWP CJmr
} vmW4 3K;
} s fxQ
<aR8fU
;K:)R_H
//打印回应的头信息 >Rw[x
public void logResponseHead(HttpURLConnection con) f!~gfnn
{ =>Vo|LBoe
for(int i=1;;i++) )POuH*j
{ r[zxb0YA
String header=con.getHeaderFieldKey(i); 1FS Jqad
if(header!=null) \k1psqw^O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); J(0.eD91v
Utility.log(header+" : "+con.getHeaderField(header)); h$p]#]uMb
else H[guJ)4#@
break; !aD/I%X
} Zi=Nr3b
} ?L$ Dk5-W
f~u]fpkz
Ctxs]S tU%
public void splitterStop() ;f7(d\=y
{ q@ >s#
bStop = true; jd$uOn.r
} :J-@+_J
a[:0<Ek
n^|n6(EZ
} =Uta5$\a)
d_&R>GmR$
:luVsQ
/* 0(;d<u)fS
**FileAccess.java &inu mc
*//文件访问(定位，写) 8H3|i7.1h
package NetFox; @eN x:}
import java.io.*; x-k}RI
?5nF` [rx
ZD] ^Y}
public class FileAccessI implements Serializable{ EZz Ox(g
@<e+E"6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z!5^UD8"W
RandomAccessFile oSavedFile; K*Zf^g m
long nPos; #CoJ S[t
%^m6Q!
&dZ-}. af
public FileAccessI() throws IOException >[=q9k
{ ,V!s w5_5m
this("",0); cA1"Nek
} ja}_u}:
4;_{*U-
7</&=lly
public FileAccessI(String sName,long nPos) throws IOException ;BqYhi
{ "jzU`
oSavedFile = new RandomAccessFile(sName,"rw"); 9@ 6y(#s
this.nPos = nPos; (Bd8@}\u_
oSavedFile.seek(nPos); v2:A 4Pd:+
} tK6z#)
dJM)~Ay-
W XDl\*n
public synchronized int write(byte[] b,int nStart,int nLen) 3(G}IWPq<
{ <<gk<_7`
int n = -1; D(D:/L8T,
try{ 5BCXI8Ox9x
oSavedFile.write(b,nStart,nLen); 9S@PY_ms
n = nLen; O^48c$Apv
} .{x-A{l
catch(IOException e) Vo<V!G{
{ -! Hn,93
e.printStackTrace (); $-m@cObw!.
} EV| 6._Z(D
a}ogNx
eWSA
return n; s~$ZTzV
} f/RzE
5mUHk]W
f4)fa yAVp
} `P<}MeJ\l
sL|*0,#K
7N,E%$QL
/* B)g7MG
**SiteInfoBean.java js)M c*]&
*/ %719h>$
package NetFox; -jdS8n4
ra=U,
|uId:^{
public class SiteInfoBean { wUj[c7Y%
Meo(|U
4;'o`K~*
private String sSiteURL; //Site's URL Y~#m-y
private String sFilePath; //Saved File's Path <7R\#
private String sFileName; //Saved File's Name V @8+
private int nSplitter; //Count of Splited Downloading File 3maiBAOKz
UXwnE@`F
mH2XwA|
public SiteInfoBean() Tt#4dm-
{//nSplitter的缺省值为5 A@xa$!4}
//default value of nSplitter is 5 ;`',M6g
this("","","",5); <dl:';@a-
} 6r{NW9y'
;rZR9fR
OjTb2[Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |l)SX\Qf`@
{ esU9
sSiteURL= sURL; ;+] mcgN!
sFilePath = sPath; (CFm6p'RZ
sFileName = sName; ZN#mu]jC?
this.nSplitter = nSpiltter; cO%-Av~P
IHHL. gT
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} F \6-s`(
chk1tFV
QG {KEj2V
public String getSSiteURL() \Fg%V>
{ dPZrX{ c
return sSiteURL; NQ~keN
} 5e=9~].7
Hy=';Ccn}
7pf]h$2
public void setSSiteURL(String value) -L&r2RF/
{ K}7E;O5m"
sSiteURL = value; koDIxj'%X
} \6AYx[|
ieuq9ah#
:bt;DJ@
public String getSFilePath() Em8q1P$tm>
{ 3NU{7,F
return sFilePath; z6 T3vw
} mU@pRjq=
f_v@.vnn.
T40&a(hXQ
public void setSFilePath(String value) EQ< qN<uW
{ Z./$}tVUG
sFilePath = value; %;ST7
} E;m]RtvH
VRden>vKN
%L(;}sJ.
public String getSFileName() SR)jJ=R3
{ mQ(6ahD U
return sFileName; ,F}\njL
} tDw(k[aK@
z OwKh>]
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public void setSFileName(String value) G*;?&;*
{ wJc~AP)I%z
sFileName = value; [0vgA#6I
} *Rm"3S
ws}cMX]*
Xa o*h(Q@L
public int getNSplitter() ,', S
{ )B"k;dLm
return nSplitter; W^dk:
} })#VO-J
T($d3Nn1
uBpnfIe
public void setNSplitter(int nCount) @ ;T|`Y=7
{ b0X<)1O
nSplitter = nCount; :\hcl&W:
} j'L/eps?S
} ]k+XL*]'A
S+wy^x@@
YkWv*l
/* arVu`pD*n
**Utility.java ki|KtKAu_9
*/ LAs#g||M
package NetFox; @6["A'h
4)Jtc2z7Z\
c_V^~hq
public class Utility { j8Pqc]
CG#lpAs
srS2v\1:
public Utility() rF@njw@
{ /;5U-<qf
y5@#leM
-9PJ4"H
} -d-vzri
OdKfU^
//线程睡眠 S7!+8$2mc_
public static void sleep(int nSecond) /H (55^EMZ
{ rgo#mTQ_
try{ yP<ngi^s=
Thread.sleep(nSecond); ujin+;1
} z6'Cz}%EP'
catch(Exception e) 3#\++h]QZ
{ s+m3&(X
e.printStackTrace (); Ga<Uvr%+
} Ow"e3]}Mt
} }>93X0%r
d9=i{i3
//日志 r~[Bzw"c
public static void log(String sMsg) nu(;yIRP
{ Ppton+?(
System.err.println(sMsg); mV>l`&K=
} d/&W[jJ
a^vTBJXo
iY,FfuE
public static void log(int sMsg) ZA1:Y{V
{ NZb}n`:
System.err.println(sMsg); "1P[D'HV4|
} AONEUSxJ
} '^|u\$&U
M&[bb $00j
8NZQTRdH
/* bmzY^ %a
**TestMethod.java K0aT(Rc e
*/ :kMF.9U:
package NetFox; W(jOD,QMB
ikd1KF+I
WqO4_;X6/
public class TestMethod { )5[OG7/g
c80Ffq
gf ?_tB0C
public TestMethod() ROhhd.
{ ///xx/weblogic60b2_win.exe H8x66}
try{ T?g%I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); c 8t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y&uwi:_g
SiteFileFetch fileFetch = new SiteFileFetch(bean); h}y]Pt?
fileFetch.start(); Zxw cqN
} @=ro/.
catch(Exception e){e.printStackTrace ();} +$YHdgZ.
7gc?7TM
ZX8AB
} "Cz0r"N
unF=";9H
bu8AOtY9E-
public static void main(String[] args) Z35(f0b
{ yE#.Q<4
new TestMethod(); EJW}&e/
} 4{QD: D(D
} 9u;/l#?@T
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