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)); i*l-w4D^U
} ]>T4\?aC
for(int i=0;i<nEndPos.length-1;i++) |A/)b78'u
{ >0c4C<_
nEndPos = nStartPos[i+1]; @b]?Gg
} 9vL n#_
nEndPos[nEndPos.length-1] = nFileLength; z]d2 rzV(_
} Kh'7N!
} MpCK/eiC
/&jh10}H
j~;kh_
//启动子线程 bd& /B&a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Xe. az
for(int i=0;i<nStartPos.length;i++) xhTiOt6l
{ >3SZD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yKb+bm&5:'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NpLO_-
nStartPos,nEndPos,i); YEiQ`sYKG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lbwc2Q,.-
fileSplitterFetch.start(); TDY2 M
} <RaUs2Q3.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6aMG!_jC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {1VMwANj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :d{-"RAG"
nEndPos = " + nFileLength); !M*$pQi}
// fileSplitterFetch[nPos.length-1].start(); XI/LVP,.
kaG@T,pH(
&CcUr#|
//等待子线程结束 s%OPoRE
//int count = 0; PN"s^]4
//是否结束while循环 oEN^O:9e
boolean breakWhile = false; ed\umQ]
%K/zVYGm&
Z!eW_""wp
while(!bStop) tQYkH$e`/{
{ u301xc,N<z
write_nPos(); lk/[xQ/
Utility.sleep(500); B3NDx+%m
breakWhile = true; #fQ}8UxU,
[5T{`&
e0&x?U*/
for(int i=0;i<nStartPos.length;i++) Wm#F~<$
{ 6-6ha7]s
if(!fileSplitterFetch.bDownOver) X:kqX[\>
{ q37d:Hp
breakWhile = false; x<gP5c>zm
break; s-lNpOi
} Xub<U>e;b
} (_.0g}2
if(breakWhile) E#A%aLp0E
break; D.:6X'hp
aEvW<jHh
kh5VuXpe
//count++; )/mBq#ZS
//if(count>4) d")TH3pG
// siteStop(); gi#g)9HG
} !Sj0!\
W9M~2< L
%}/|/=
System.err.println("文件下载结束！"); tmVGJ+gz
} v3I-i|L<)
catch(Exception e){e.printStackTrace ();} P g.j]
} Bh0hUE
FzM<0FJRX
<Y"h2#M"
//获得文件长度 mR3-+dB/
public long getFileSize() 5!V%0EQqw
{ q>5K:5
int nFileLength = -1; NO'37d
try{ ^X\SwgD2w
URL url = new URL(siteInfoBean.getSSiteURL()); Uz$.sa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =b_/_b$q
httpConnection.setRequestProperty("User-Agent","NetFox"); QFX/x
(Rs052m1
K}a3Bj,
int responseCode=httpConnection.getResponseCode(); (@nEe?
if(responseCode>=400) J]4pPDm
{ <%ba 3<sg
processErrorCode(responseCode); Z#znA4;)
return -2; //-2 represent access is error T6^H%;G
} "fN=Y$G
qS?uMms7w
`E:&a]ul
String sHeader; kPvR ,
J<h!H
/c|X:F!;X#
for(int i=1;;i++) RTQtXv6mD
{ -F~"W@9r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4uy:sCmu
//Utility.log(in.readLine()); O;83A
sHeader=httpConnection.getHeaderFieldKey(i); !HCuae3_
if(sHeader!=null) =tQ^t4_
{ 0/TP`3$X#"
if(sHeader.equals("Content-Length")) D4IP$pAD
{ oUNuM%g9Dy
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dhze2q)o
break; Ra)AQ n
} _/[}PQC6G
} S17 c#6vT
else ^_5t5>
break; d]r?mnN W
} 155vY
} F!qt=)V@w
catch(IOException e){e.printStackTrace ();} o8c5~fG1
catch(Exception e){e.printStackTrace ();} <Gw>}/-^
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.9VhDrCK
Utility.log(nFileLength); k^Qd%;bdF
Z3qr2/
AQm#a;
return nFileLength; >hv8zHOO:
} ?)V|L~/
M'5PPBSR
6.6;oa4j
//保存下载信息（文件指针位置） E x)fXQ+
private void write_nPos() vp&N)t_
{ mbZn[D_zi
try{ (U([T-H
output = new DataOutputStream(new FileOutputStream(tmpFile)); Lc! t
output.writeInt(nStartPos.length); cTa$t :K@
for(int i=0;i<nStartPos.length;i++) 6R#.AD\
{ PTP0 _|K
// output.writeLong(nPos); ##5e:<c&[
output.writeLong(fileSplitterFetch.nStartPos); G}LOQ7
output.writeLong(fileSplitterFetch.nEndPos); _ZHDr[
} GAU7w"sE
output.close(); (MzThGJK_
} ]47!Zo,
catch(IOException e){e.printStackTrace ();} !t!'
catch(Exception e){e.printStackTrace ();} k< $(
} .g>0FP
8;y\Ln?B
.kc{)d*0K
//读取保存的下载信息（文件指针位置） }DFZ9,gQ
private void read_nPos() &1FyauH
{ 7-("ppYX=
try{ 4Hq6nT/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]FEsN6
int nCount = input.readInt(); ^KUM4. 6
nStartPos = new long[nCount]; 3eN(Sw@p
nEndPos = new long[nCount]; hka`STK{
for(int i=0;i<nStartPos.length;i++) [13NhF3.P
{ D!rD-e
nStartPos = input.readLong(); r1a/'+
nEndPos = input.readLong(); &UIS17cT
} xp%LXxj
input.close(); Z+agS8e(
} v(`5exWV
catch(IOException e){e.printStackTrace ();} /E^j}H{
catch(Exception e){e.printStackTrace ();} KvmXRf*z
} 6yK"g7
C)BVsHT4
seiE2F[
private void processErrorCode(int nErrorCode) !laOiH
{ IeAUVRS)
System.err.println("Error Code : " + nErrorCode); j"9Zaq_
} 'tY y_
4%*`'o$_
, %A2wV
//停止文件下载 g-<[* nF
public void siteStop() >x8~?)7z
{ rq|>z.
bStop = true; ,B$e'KQ
for(int i=0;i<nStartPos.length;i++) e_dsBmTh
fileSplitterFetch.splitterStop(); cdTG ]n
Z&5cJk W
B&?xq)%*#
} 9&Ny;oy#6
} K-n]m#U4o
//负责部分文件的抓取 \z?-
**FileSplitterFetch.java X!K:V~WG
*/ #Ti5G"C
package NetFox; eb7~\|9l1i
Hr/Q?7g
`q+Ug
import java.io.*; \4n9m
import java.net.*; lFD/hz7lc
[cT7Iqip
LEA^o"NW.
public class FileSplitterFetch extends Thread { m_b_)/
[Y8ot-6
G&#l3bkQ
String sURL; //File URL |3=tF"h
long nStartPos; //File Snippet Start Position :s#&nY
long nEndPos; //File Snippet End Position Xagz(tm/
int nThreadID; //Thread's ID VV"1IR
boolean bDownOver = false; //Downing is over \= Wrh3
boolean bStop = false; //Stop identical w C-x'
FileAccessI fileAccessI = null; //File Access interface T^H`$;\
M9/J!s
I ka V g L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >:P-3#e*
{ M3YC@(N% k
this.sURL = sURL; 8g6G},Y0
this.nStartPos = nStart; `.YMbj#T
this.nEndPos = nEnd; E[tEW0ub
nThreadID = id; #$v,.Yk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 o_?A^u
} >qci$
6mC% zXR5
V?4G~~F
public void run() V#\iO
{ 1VB{dgr
while(nStartPos < nEndPos && !bStop) aKw7m={
{ \g:Bg%43h
gkld}t*U
&I?d(Z=:\
try{ kRB2J3Nt.
URL url = new URL(sURL); %-3wR@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !\|L(Paf
httpConnection.setRequestProperty("User-Agent","NetFox"); ;\gHFG}
String sProperty = "bytes="+nStartPos+"-"; y-vQ4G5F|
httpConnection.setRequestProperty("RANGE",sProperty); Te@=8-u-
Utility.log(sProperty); rNeSg=j
zwdi$rM5
Q9sxI}D )R
InputStream input = httpConnection.getInputStream(); qrY]tb^K
//logResponseHead(httpConnection); $GX9-^og=T
B2)SNhF2Y
?#VkzT
byte[] b = new byte[1024]; tkf^sGgNO
int nRead; *Zz hN]1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LAv!s/O$=
{ |oTA$bln
nStartPos += fileAccessI.write(b,0,nRead); 5 DvD
//if(nThreadID == 1) }+BbwBm&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z?Qt%1q
} P*{*^DN
T<~?7-O"
)U:W 9%
Utility.log("Thread " + nThreadID + " is over!"); <9aa@c57
bDownOver = true; ~k/GmH
//nPos = fileAccessI.write (b,0,nRead); 8% `Jf`
} 3<ry/{#%
catch(Exception e){e.printStackTrace ();} j(];b+>
} BYXMbx
} +{@hD+
gIcm`5+T
#B8V2_M
//打印回应的头信息 6"_ytqw7
public void logResponseHead(HttpURLConnection con) rPF2IS(5
{ XV:icY
for(int i=1;;i++) k{.`=j
{ >kG: MJj
String header=con.getHeaderFieldKey(i); 'Y:ZWac,
if(header!=null) wQ~F%rQ$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :DR}lOi`
Utility.log(header+" : "+con.getHeaderField(header)); k+y>xI,
else ^Mi&2AvS
break; .eG_>2'1
} KU)~p"0[6]
} ^fT?(y_=e
*N3X"2X:
Xjnv8{X
public void splitterStop() _U`1BmTC2
{ %$}*y
bStop = true; <#No t1R
} GB` G(a
av4g/7=
ip2BvN&
} {igVuZ(>en
Evb %<`gd
ewp&QH4
/* Nt P=m @
**FileAccess.java FOD_m&+
*//文件访问(定位，写) ?;?$\b=
package NetFox; [Z{0|NR
import java.io.*; `HJRXoLySW
9zD^4j7
TaE&8;H#N
public class FileAccessI implements Serializable{ br_D Orq|
iBy &#^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @#KZ2^
RandomAccessFile oSavedFile; <hM`]/J55
long nPos; A]q"+Z]
Tq`rc"&7u
R[{s\
public FileAccessI() throws IOException iK <vr
{ 7S)u7
this("",0); eBxOa
} 18kzR6(W
o2r)K AA
d6;"zW|Ec
public FileAccessI(String sName,long nPos) throws IOException >Sua:Uff
{ D}6~2j
oSavedFile = new RandomAccessFile(sName,"rw"); CiTjRJ-ZW)
this.nPos = nPos; pv){R;f
oSavedFile.seek(nPos); `w/`qG:dK
} GV(@(bI*
DSc:>G
p:CpY'KV_
public synchronized int write(byte[] b,int nStart,int nLen) D+xHTQNTL
{ )TV{n#n
int n = -1; R3ru<u>k&
try{ sqP (1|9
oSavedFile.write(b,nStart,nLen); 1*ui|fuK
n = nLen; xix:= a
} jj8h>"d
catch(IOException e) @O Rk
{ euc|G Xs
e.printStackTrace (); *mTx0sQz(J
} 1Wy0#?L
N)N\iad^
y:+4-1
return n; f*&4d
} @ob4y
(zL(
}[m,HA<j
} WwBs_OMc
z~y=(T
:q,tmk h
/* gS$?#!f
**SiteInfoBean.java N#"(
*/ UjrML
package NetFox; zs@xw@
}*s%|!{H
MeXGE
public class SiteInfoBean { 380M&Guh
cas5
I#U"DwM
private String sSiteURL; //Site's URL E ) iEWc
private String sFilePath; //Saved File's Path |SfmQ;
private String sFileName; //Saved File's Name 9et%Hn.K'
private int nSplitter; //Count of Splited Downloading File N5\]VCX
z c7P2@
!HPye@Ua
public SiteInfoBean() L5-Kw+t
{//nSplitter的缺省值为5 d2XSw>
//default value of nSplitter is 5 ,U^V]jC
this("","","",5); 2J5RZg9jL
} B8sc;Z.
B%Vz -t
Tz{f5c&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N|53|H
{ xvx+a0 A
sSiteURL= sURL; />q?H)6
sFilePath = sPath; 1so9w89
sFileName = sName; ueD_<KjE=
this.nSplitter = nSpiltter; 4itadQS
%;-]HI
u~y0H
} fce~a\y0
r[}5<S Q
,8^QV3
public String getSSiteURL() ym~
{ i{+W62k*
return sSiteURL; Sdn4y(&TP
} Td"_To@jd
"cVJqW
K~DQUmU@
public void setSSiteURL(String value) ] 3UlF'{
{ AYnk.H-v
sSiteURL = value; -cqR]'u
} 9p{7x[C
r{pbUk
*t3uj
public String getSFilePath() &W@#pG
{ WMw^zq?hd@
return sFilePath; Nxd<#p
} gcKXda(
>.X& v
1U(P0$C
public void setSFilePath(String value) fCa*#ME
{ }cPH}[$zF
sFilePath = value; rMy(NAo_
} zs<2Ozv
d=v{3*a_4,
=Mby;wQ?|
public String getSFileName() ;Or]x?-
{ q{:]D(
return sFileName; nhZ^`mP
} v3q.,I_
nS5g!GYY,k
b|KlWt'
public void setSFileName(String value) f0d*%
{ Y"dUxv1Ap
sFileName = value; X}@'FxIF
} 4u.Fy<+@4M
c>}fy
(0W)Jd[
public int getNSplitter() 9yrSCDu00
{ oZCjci-
return nSplitter; xP61^*-2
} $9%UAqk9
@cC@(M~Ru
9H6%\#rw
public void setNSplitter(int nCount) 6hX[5?}
{ {/E_l
nSplitter = nCount; CqkY_z
} @7j$$
} yy(.|
5tG\5
C1ZuDL)e
/* {)L*\r
**Utility.java r-aCa/4y!
*/ }JlrWJRi
package NetFox; i+&o%nK2
t 8,VRFV
'] $mt
public class Utility { 5dXDL~/2p
j :$Ruy
4!k0
public Utility() li7"{+ct
{ #P)(/>nF
u P&<
Mr6q7
} l?Qbwv}
HV}*}Ty
//线程睡眠 OB5t+_s
public static void sleep(int nSecond) 4;D>s8dgG
{ fUV;3du
try{ :% m56
Thread.sleep(nSecond); hqwDlapTt
} ?Fp2W+M j
catch(Exception e) ?Zv>4+Y'
{ ["7]EW\!:
e.printStackTrace (); >)6d~
} id:6O+\
} iR39lOr
\>N"{T
//日志 L2}p<?f
public static void log(String sMsg) H2oD0f|
{ xwjiNJ Gj
System.err.println(sMsg); *\"+/
} ,JONc9
3U!#rz"
(\o &Gl
public static void log(int sMsg) <#%kmYSL
{ dm`:']?
System.err.println(sMsg); U0fr\kM
} z5q(
} c)B <d#
9JBVG~m+
25wvB@0&
/* -?Kd[Ma
**TestMethod.java o)r%4YOL
*/ x4^*YZc$,
package NetFox; qtYVX:M@,
h'|J$
=OR"Bd:O
public class TestMethod { <S@XK%
>m'n#=yap
jx[g;7~X
public TestMethod() (*Fb/
{ ///xx/weblogic60b2_win.exe 2'T uS?
try{ MNWuw;:v
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \VAm4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,WgEl4
SiteFileFetch fileFetch = new SiteFileFetch(bean); qx2M"uFJ
fileFetch.start(); ? e<D +
} T'${*NVn
catch(Exception e){e.printStackTrace ();} wG}Rh,
d*tn&d~k,
.\}nDT
} W~Ae&gcn#
%z"${ zw
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public static void main(String[] args) +5xk6RP
{ I6lWB(H!u
new TestMethod(); n1r'Y;G
} R!y`p:O C
} 7?W1i{(
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