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)); +Y)rv6}m
} "4`h -Y
for(int i=0;i<nEndPos.length-1;i++) {n$9o
{ egx(N <
nEndPos = nStartPos[i+1]; e_k1pox]l
} fcnbPO0M
nEndPos[nEndPos.length-1] = nFileLength; +c}fDrr)
} ;OPzT9
} {-Yp~HQF
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//启动子线程 q6H90Zb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !rTh+F*
for(int i=0;i<nStartPos.length;i++) aWOApXJ
{ JaG<.ki
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~`T(mh',
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZzzQXfA#
nStartPos,nEndPos,i); iknBc-TLD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9Hlu%R
fileSplitterFetch.start(); hd/5*C{s
} qIA!m .GC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,8+SQo#3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); p8Lb*7W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", PovPO
nEndPos = " + nFileLength); _)2NFq
// fileSplitterFetch[nPos.length-1].start(); cU%#oEMf<
uZm<:d2%)
`5[VO
//等待子线程结束 <gf:QX!
//int count = 0; ?v8RY,Q30
//是否结束while循环 \&@Tq-o
boolean breakWhile = false; #^!oP$>1
dlJkxEh2
cg1<
while(!bStop) <wj2:Z0
{ r{>tTJFD(:
write_nPos(); {< jLfL1
Utility.sleep(500); %J~8a_vO
breakWhile = true; ]~3wq[O
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/A|ofAr)
for(int i=0;i<nStartPos.length;i++) KM< M^l_Q
{ si3i#l&.b_
if(!fileSplitterFetch.bDownOver) )bi*y`UM]
{ @hl5^d"l
breakWhile = false; VI" ,E}
break; Gp@Y=mU
} 8 l}tYl`|
} | 2p\M?@
if(breakWhile) 8{%/!ylJz
break; L!mQP
;X|;/@@
zr84%_^
//count++; *v l_3S5_
//if(count>4) HmbTV(lC
// siteStop(); GdL\
} 8Nci1o
=*"Amd,
uW Q`
System.err.println("文件下载结束！"); ik7#Og~3
} gqZ7Pro.
catch(Exception e){e.printStackTrace ();} uZd)o AB
} MT%ky
hLx*$Z>
3w!oJB
//获得文件长度 wpx,~`&
public long getFileSize() \&ERSk2
{ GlQ=M)E
int nFileLength = -1; aH'^`]'_=
try{ |06J4H~k
URL url = new URL(siteInfoBean.getSSiteURL()); 7dV^35 KP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0S/&^
httpConnection.setRequestProperty("User-Agent","NetFox"); \ E[0KvN;O
PCt&66F
8Q#&=]W$
int responseCode=httpConnection.getResponseCode(); sDJ5'ul
if(responseCode>=400) Br\/7F
{ gJvc<]W8!
processErrorCode(responseCode); 2kCJqyWy
return -2; //-2 represent access is error 6K?+adKlc
} ^4 es
5>h2WL
pA+Qb.z5z
String sHeader; -lb}}z+/
/*rMveT
oDKgW?x
for(int i=1;;i++) Pbm;@V
{ Wd~}O<"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9FPl
//Utility.log(in.readLine()); s_D7?o
sHeader=httpConnection.getHeaderFieldKey(i); K8284A8v
if(sHeader!=null) FY#`]124*
{ 1D=My1B
if(sHeader.equals("Content-Length")) GbB&kE3KP
{ Haq23K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eUF PzioW
break; 1REq.%/=
} Gp32\^H|<
} 2z )h,<D
else _@?]!J[
break; w:z_EV!&
} r'xa'6&
} -J? df
catch(IOException e){e.printStackTrace ();} f4@Dn >BJ
catch(Exception e){e.printStackTrace ();} z81I2?v[Jr
BtU,1`El5
El"XF?OgpP
Utility.log(nFileLength); tC|5;'m.2
Fo~C,@/Qt
2<u vz<B
return nFileLength; Z(xn-
} V :d/;~
hDmVv;M:
*2;w;(-s
//保存下载信息（文件指针位置） ]S;e#u{QE
private void write_nPos() f)"O( c
{ x6:$lZ(
try{ ~POe0!}
output = new DataOutputStream(new FileOutputStream(tmpFile)); %pTbJaM\U
output.writeInt(nStartPos.length); 0FEb[+N
for(int i=0;i<nStartPos.length;i++) QbOmJQ
{ ;YK^&!N
// output.writeLong(nPos); ;=B&t@
output.writeLong(fileSplitterFetch.nStartPos); IXd&$h]Lq
output.writeLong(fileSplitterFetch.nEndPos); ~jF5%Gu
} |$bZO`^
output.close(); 7J$ ^R6rh
} 3@6f%Dyj
catch(IOException e){e.printStackTrace ();} Oe2Tmvl
catch(Exception e){e.printStackTrace ();} &w/aQs~
} U$0#j
r}*2~;:pW
9H.E15B
//读取保存的下载信息（文件指针位置） <C CEqY4
private void read_nPos() 0{AVH/S
{ :hxfd b-
try{ 9J2%9,^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FUq@ dUv
int nCount = input.readInt(); BT`/OD@
nStartPos = new long[nCount]; < >f12pu
nEndPos = new long[nCount]; hr]NW>;
for(int i=0;i<nStartPos.length;i++) /\#qz.c2K
{ N;Hf7K
nStartPos = input.readLong(); %v}:#_va]
nEndPos = input.readLong(); .HGEddcC
} hQ<"
input.close(); XPWK"t01
} mYa0_P%^
catch(IOException e){e.printStackTrace ();} ~^Vt)/}Q
catch(Exception e){e.printStackTrace ();} HnOp*FP
} ''f
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7cvbYP\<lv
private void processErrorCode(int nErrorCode) hnE@+(d=qJ
{ $7|0{Dw
System.err.println("Error Code : " + nErrorCode); B;G|2um:$
} {#Gr=iv~N
`[o^w(l:5@
tYmWze.j
//停止文件下载 ,`-6!|:
public void siteStop() )G*Hl^Z;4
{ wPqIy}-
bStop = true; Qj0@^LA
for(int i=0;i<nStartPos.length;i++) ZH&%D*a&
fileSplitterFetch.splitterStop(); |? r,W~9`
c#CX~
;[dcbyu@
} >@TZYdl
} !>t|vgW
//负责部分文件的抓取 rJ!xzge;G
**FileSplitterFetch.java =A=er1~%
*/ c*1B*_08
package NetFox; 3(FJ<,"D}
'lIT7MK
:/Sx\Nz78
import java.io.*; M[TgNWl/[
import java.net.*; eJJvEvZ,
7i6-Hq
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public class FileSplitterFetch extends Thread { R<k4LHDy
Fz>J7(Y.j
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String sURL; //File URL Is?0q@
long nStartPos; //File Snippet Start Position T4\,b
long nEndPos; //File Snippet End Position trgj]|?M
int nThreadID; //Thread's ID Z8nNZ<k
boolean bDownOver = false; //Downing is over LD^V="d
boolean bStop = false; //Stop identical % YU(,83(+
FileAccessI fileAccessI = null; //File Access interface 4y)"IOd#|
oD!72W_:
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3G5i+9Nt.L
{ Ij{{Z;o3
this.sURL = sURL; ? )0U!)tK
this.nStartPos = nStart; *,pG4kh!
this.nEndPos = nEnd; 0XXu_f@]9
nThreadID = id; tlvLbP*r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r6MQ|@
} r 97 VX>
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~}wPiu,
public void run() P9Rq'u
{ T7!a@
while(nStartPos < nEndPos && !bStop) |\N[EM%.@
{ .c~;/@{
5O*.qp?
c%i/ '<Afr
try{ 2r[Q$GPM<
URL url = new URL(sURL); fqvA0"tv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SDdK5@1O4o
httpConnection.setRequestProperty("User-Agent","NetFox"); bl}$x/
String sProperty = "bytes="+nStartPos+"-"; f]o DZO%^
httpConnection.setRequestProperty("RANGE",sProperty); 9e8@0?0
Utility.log(sProperty); oa;[[2c
=_L"x~0I-
1Qf5H!5vx
InputStream input = httpConnection.getInputStream(); Mgf80r=
//logResponseHead(httpConnection); t{84ioJ"$
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byte[] b = new byte[1024]; b6);bX>e
int nRead; pm<<!`w"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }$m_):t@@
{ u4+)lvt
nStartPos += fileAccessI.write(b,0,nRead); c67O/ B(
//if(nThreadID == 1) Ak>RLD25_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =X-$kk
} 0~n=|3*P
^HC! my
iFga==rw
Utility.log("Thread " + nThreadID + " is over!"); jC;XY!d6
bDownOver = true; ^$rt|]
//nPos = fileAccessI.write (b,0,nRead); 1N:eM/a
} d![EnkyL;
catch(Exception e){e.printStackTrace ();} @@!t$dD
} 7jEAhi!Cq(
} Z@~8iAgE
W&Fa8
PjRKYa_U
//打印回应的头信息 3tOnALv
public void logResponseHead(HttpURLConnection con) QE-t v00
{ l2n>Wce9
for(int i=1;;i++) I>ofSaN
{ 0]i#1Si~@
String header=con.getHeaderFieldKey(i); a)`h*P5@
if(header!=null) .Jou09+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \N/T^,
Utility.log(header+" : "+con.getHeaderField(header)); PT>,:zY
else #pOW2 Uj8\
break; EeL~`$f
} ` LU&]NS3
} kiqq_`66
'4N[bRCn
(lt/ t
public void splitterStop() !X |Tf
{ %T1(3T{Li
bStop = true; ]+fL6"OD/2
} ){8^l0b
~#) DJ
?t?!)#X
} ]9b*!n<z
H( cY=d,
#?8'Z/1)
/* [.3M>,)+-
**FileAccess.java .,tf[w 71
*//文件访问(定位，写) :5C9uW#
package NetFox; GT#iY*
import java.io.*; MF%9
K$f~Fft
ob-be2EysH
public class FileAccessI implements Serializable{ `?`\!uP"
?vM{9!M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Hyc19|
RandomAccessFile oSavedFile; +O\6p
long nPos; 1gCp/m2r7
' 71D:%p
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public FileAccessI() throws IOException kj+AsQC,
{ umD .
this("",0); `[Z?&'CRQ
} oh,Nu_!
IsnC_"f
S@T>u,t'
public FileAccessI(String sName,long nPos) throws IOException +gK7`:v4O*
{ dHd{9ftyF
oSavedFile = new RandomAccessFile(sName,"rw"); B#sc!eLmU&
this.nPos = nPos; qmJFXnf
oSavedFile.seek(nPos); %o*afd
} X8?|5$Ey
4sROMk=l
[+ 1([#
public synchronized int write(byte[] b,int nStart,int nLen) )mp0k%
{ VYlg+MlT0
int n = -1; &5C%5C~ch
try{ h:j-Xd$H+
oSavedFile.write(b,nStart,nLen); nD E5A
n = nLen; T>W(Caelq
} tAYu|\]
catch(IOException e) ^VoQGP/cl
{ Ml0d^l}'
e.printStackTrace (); BKVvu}V(o
} wk)gxn1A,
@Q TG
Z#^2F8,]
return n; &W|'rA'r
} 21w<8:Vg
I"Y?vj9]
A}[Lk#|n
} /T*{Mo{B
vC+mC4~/(
Q7`zrCh
/* o$Hc5W([Z
**SiteInfoBean.java DHm$gk
*/ v)rN]b]
package NetFox; +h*&r~T
S.M< (
jZ.+b j >
public class SiteInfoBean { +ZGOv,l
NE3G!qxL
+.[#C5
private String sSiteURL; //Site's URL >8jDW "Ua
private String sFilePath; //Saved File's Path 5M*q{kX)
private String sFileName; //Saved File's Name ZhM-F0;`
private int nSplitter; //Count of Splited Downloading File o<T>G{XYB
dI'C[.zp[
e`8z1r
public SiteInfoBean() gY;N>Yq,C
{//nSplitter的缺省值为5 vjbot^W9
//default value of nSplitter is 5 6U# C
this("","","",5); ;?%2dv2d
} Q;5aM%a`
&[JI L=m5
b@5&<V;r2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vJXd{iQE@C
{ H+_oK ]/
sSiteURL= sURL; x"U/M?l
sFilePath = sPath; QT^( oog=
sFileName = sName; I]ywO4
this.nSplitter = nSpiltter; zXZy:SD
:sM|~gT
<}B|4($
} +Y 3_)
0-FwHDxw
xAz gQ
public String getSSiteURL() ^W#[6]S
{ @yobT,DXi
return sSiteURL; XTHrf'BU
} 'KyT]OObS
K\n %&w
$m{\<A
public void setSSiteURL(String value) Wpj.G
{ nc@ul')
sSiteURL = value; x-Xb4?{
} 6^|bKoN/ f
`qs'={YtU
C|z`hNp
public String getSFilePath() ~oSLWA9
{ cDE?Xo'!
return sFilePath; '!IX;OSjH
} Fd|:7NRA<
<*4=sX@
{jlm]<:&Z
public void setSFilePath(String value) ?;uzx7@F
{ .[K{;^>
sFilePath = value; 9HP)@66
} Oi l>bv8
l 4~'CLi
MY1 tYO
public String getSFileName() RAf+%h*
{ &QCqaJ-
return sFileName; V 9=y@`;
} w&f29#i;b
unjo&
f ( UcJx
public void setSFileName(String value) Fi*6ud\n!
{ r@s, cCK9?
sFileName = value; ]l+2Ca:-[j
} ub.pJJlC
:!{aey
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public int getNSplitter() `EWeJ(4Z@
{ )Tb{O
return nSplitter; 4p %`Lv
} :(I)+;M}P
@JN%P}4)
)t)tk=R9N
public void setNSplitter(int nCount) dqd Qt_
{ B%'Np7
nSplitter = nCount; ,9W0fm\t
} vi lNl|
} ,wZ[Y 3
xB9^DURr\
7g(rJGjtg
/* Hi.JL
**Utility.java >@]E1Qfe
*/ ;'p0"\SV
package NetFox; 73N%_8DH
a.w,@!7
1d-j_H`s
public class Utility { %NxNZe
<NS=<'U
xbn+9b
public Utility() 4b7}Sr=`
{ S0p]:r";x
E 8,53$
EHo"y.ODg
} Qj3UO]>
17};I7
//线程睡眠 G_dia6
public static void sleep(int nSecond) *OsXjL`f
{ O#u)~C?)8
try{ ~ RTjcE
Thread.sleep(nSecond); @h^5*M
} gdkO|x
catch(Exception e) hA/FK
{ 5!y3=.j
e.printStackTrace (); W>1\f0'
} rEddX
} S93NsrBbY
C"0gAN
//日志 bS0^AVA
public static void log(String sMsg) Zsf<)Vx
{ guFR5>-L
System.err.println(sMsg); Fb-NG.Z#
} LM*9b
CR, Y%0vQ
a?+) K
public static void log(int sMsg) Z39^nGO
{ >1joCG~
System.err.println(sMsg); ?]paAP;4
} 1X#`NUJ?2
} w8@MUz}/#
xES+m/?KlZ
6EPC$*Xp!
/* JTz1M~
**TestMethod.java @&h<jM{D
*/ 0*tEuJ7
package NetFox; * z{D}L-&
gb@!Co3
<u^41
public class TestMethod { ! '2'db
u# %7>=
&s] s]V)
public TestMethod() egP3q5~
{ ///xx/weblogic60b2_win.exe kW-5H;>
try{ #!,xjd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,pAMQ5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [ >vS+G
SiteFileFetch fileFetch = new SiteFileFetch(bean); y& Dd
fileFetch.start(); 8mCr6$|%
} %*jpQOw
catch(Exception e){e.printStackTrace ();} XWB>' UDQ#
tQ|b?3
]JhtO{
} a"WnBdFZ
~vF.k,
n,AN&BZ
public static void main(String[] args) ^//N-?Fx
{ u2Rmp4]
new TestMethod(); (:[><-h.
} zIdQ^vm8Q
} *>\RGL;]8
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