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)); 1TKEm9j]u
} hHcJN
for(int i=0;i<nEndPos.length-1;i++) P+[QI U
{ TqIAWbb&
nEndPos = nStartPos[i+1]; "gFxfWIA
} s(Z(e %
nEndPos[nEndPos.length-1] = nFileLength; YTQ5sFuGM
} j]rXoV>
} /+>)"D6'
ZTN(irK
&|)hCJu
//启动子线程 ZAMeqPt
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; DW#Bfo
for(int i=0;i<nStartPos.length;i++) ,Kuk_@(}5~
{ >9ob*6q,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1Fv8T'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TYYp"wx
nStartPos,nEndPos,i); G 0hYFc u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @&;(D!_&
fileSplitterFetch.start(); Z+ixRch@-s
} v2d<o[[C
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?-pi,O~(p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); BWWq4mdb{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hw;0t,1
nEndPos = " + nFileLength); 'iJDWxCD
// fileSplitterFetch[nPos.length-1].start(); =/[ltUKs:a
.Y;b)]@f
yH^f\u0
//等待子线程结束 n|WfaJQZ
//int count = 0; F9-[%l
//是否结束while循环 uS~#4;R
boolean breakWhile = false; 4CLsY n?
n=q=zn;
uKv&7p@|_)
while(!bStop) hi!`9k
{ %dc3z"u
write_nPos(); 3?Lgtkb8
Utility.sleep(500); wzd`l?o,
breakWhile = true; Ejv%,q/T(
cph~4wCS[U
-;$nb~y
for(int i=0;i<nStartPos.length;i++) ;J]25j]]
{ w!\3ICB
if(!fileSplitterFetch.bDownOver) TXjloGv^
{ _K'7(d0z
breakWhile = false; JBz}|MD
break; 9RH"d[%yc}
} BWh}^3?l
} :}Ok$^5s
if(breakWhile) s.VA!@F5
break; K1OkZ6kl
r$ =qQ7^#
zN%97q_
//count++; yG\UW&P
//if(count>4) 1]T|6N?
// siteStop(); /%!~x[BeJ>
} e'34Pw!m
Pe}PH I
u^=`%)
System.err.println("文件下载结束！"); V>Fesm"aq
} %t*[T
catch(Exception e){e.printStackTrace ();} ~h! 13!
} GX }q9
/4*WDiH
#jBN?Z#
//获得文件长度 =s;M]:
public long getFileSize() 4J5pXlzV
{ [[WF0q
int nFileLength = -1; !;v.>.lw
try{ OUI6 ax\[
URL url = new URL(siteInfoBean.getSSiteURL()); g\Ak;03n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9C/MRmv`
httpConnection.setRequestProperty("User-Agent","NetFox"); v>H=,.`0\
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,(N[*)G
int responseCode=httpConnection.getResponseCode(); )o{aeV
if(responseCode>=400) m2xBS!fm
{ io.]'">
processErrorCode(responseCode); .IgRY\?Q
return -2; //-2 represent access is error 0}]SUe^
} 'H|~u&?
qM",( Bh
]]2k}A[-I
String sHeader; 5dl,co{q
QB&BTT=!
T_LLJ}6M
for(int i=1;;i++) $'{=R 45Z
{ jnJZ#=)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :U'Cor H
//Utility.log(in.readLine()); e)@3m.
sHeader=httpConnection.getHeaderFieldKey(i); /:Lu_)5
if(sHeader!=null) 7O)" `
{ &eQJfc\a
if(sHeader.equals("Content-Length")) \S4SI
{ Xgat-cy'DA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z)-c#F@%
break; s_[VHPN
} =lp1Z>
} eg<pa'Hw
else Zb_apjg[4
break; =:=/Gz1
} `s"d]/85VW
} d ~`V7B2Y
catch(IOException e){e.printStackTrace ();} g`0moXz
catch(Exception e){e.printStackTrace ();} nlGHT
3^,QIG
W\cjdd
Utility.log(nFileLength); wRvb8F0
)d`mvZBn1
Da.G4,vLh
return nFileLength; +v7) 1y
} [ MyE2^
!wE}(0BTx
Z7a945Jd
//保存下载信息（文件指针位置） ldqLM
private void write_nPos() FwG!>
{ !%)]56(
try{ 2g-` ]Vqb
output = new DataOutputStream(new FileOutputStream(tmpFile)); ny*i+4Mb
output.writeInt(nStartPos.length); !*{q^IO9v&
for(int i=0;i<nStartPos.length;i++) =(o']ZaaA
{ }m-"8\_D
// output.writeLong(nPos); IG ~`i I
output.writeLong(fileSplitterFetch.nStartPos); nZk+
output.writeLong(fileSplitterFetch.nEndPos); ;9a 6pz<
} `]i []|
output.close(); %*}Y6tl'|
} vB0RKk}d5
catch(IOException e){e.printStackTrace ();} L]%l51U
catch(Exception e){e.printStackTrace ();} `3cCH
} uLR<FpM
5's~>up&
l'[A?%L%{
//读取保存的下载信息（文件指针位置） pG3k
private void read_nPos() g>JLDQdc
{ ;i<jhNA
try{ j5$GFi\kB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o\VUD
int nCount = input.readInt(); (s<s@`
nStartPos = new long[nCount]; N2C7[z+l`
nEndPos = new long[nCount]; hz:pbes
for(int i=0;i<nStartPos.length;i++) U/ od~29
{ fmX!6Kv
nStartPos = input.readLong(); r6Aneg7
nEndPos = input.readLong(); Yk!/ow@.
} 0RFRbi@n(
input.close(); a_~=#]a
} k[j90C5
catch(IOException e){e.printStackTrace ();} U8$4 R,+
catch(Exception e){e.printStackTrace ();} Mkxi~p%<r
} WKfkKk;G
&7e)O=
qet>1<
private void processErrorCode(int nErrorCode) 8^/I>0EZ
{ X}ma]
System.err.println("Error Code : " + nErrorCode); WJH\~<{mP
} !]yO^Ob.E
KngTc(^_D
NPa\Cg[
//停止文件下载 n2B){~vE
public void siteStop() ypOLp SYk
{ kYzKU2T\W
bStop = true; >Gml4vGK
for(int i=0;i<nStartPos.length;i++) %QmxA 7fW
fileSplitterFetch.splitterStop(); i%m"@7.kk
W,5Hx1z R
=@&cHY
} s$ENFp7P
} EOj"V'!
//负责部分文件的抓取 \_V-A f{6
**FileSplitterFetch.java /P|fB]p
*/ Fb`a~c~s
package NetFox; <7SpEVQ
RD7^&
sUJ%x#u}Fk
import java.io.*; `.jzuX
import java.net.*; b//B8^Eong
x+8_4>,>Y7
%ts^Z*3u
public class FileSplitterFetch extends Thread { 2Y\ d<.M
{9Y+.46S
D"(L5jR8m@
String sURL; //File URL g[RI.&?
long nStartPos; //File Snippet Start Position i':ydDOOHA
long nEndPos; //File Snippet End Position C?v[Z]t
int nThreadID; //Thread's ID MTg:dR_
boolean bDownOver = false; //Downing is over M>9-=$7
boolean bStop = false; //Stop identical fZ04!R
FileAccessI fileAccessI = null; //File Access interface I-y#Ks1p+
KqBk~-G
#} ~qqJ G2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -}O1dEn.
{ vE@!{*
this.sURL = sURL; 0.T4{JS#
this.nStartPos = nStart; ?Nf>]|K:Q
this.nEndPos = nEnd; (~CLn;'
nThreadID = id; 5pr"d@.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +/,icA}PI
} @SZM82qU2z
{^(ACS9mL
?0? R
public void run() Q_* "SRz
{ 7S/G B
while(nStartPos < nEndPos && !bStop) HEA#bd\
{ ,@1p$n
A+6 n#
\drqG&wl
try{ (py]LBZ
URL url = new URL(sURL); w0w G-R ?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Bm&kkx.9P
httpConnection.setRequestProperty("User-Agent","NetFox"); ~|<WHHN(
String sProperty = "bytes="+nStartPos+"-"; \fA{1
httpConnection.setRequestProperty("RANGE",sProperty); bM8If"
Utility.log(sProperty); 7VcmVq}X
=mA: ctu~v
S*j6OwZ
InputStream input = httpConnection.getInputStream(); IDnC<MO>
//logResponseHead(httpConnection); 'smWLz}
>e\9Bf_
3a.kBzus
byte[] b = new byte[1024]; @u==x*{|
int nRead; 'F>'(XWWQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) NR;1z
{ ml\4xp,
nStartPos += fileAccessI.write(b,0,nRead); T,| 1g6
//if(nThreadID == 1) X[f=h=|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \j&^aAp r
} UnI48Y
-S3MH1TZ
$O9^SB
Utility.log("Thread " + nThreadID + " is over!"); Fx-8M!
bDownOver = true; 9U$EJN_G
//nPos = fileAccessI.write (b,0,nRead); ^G6RjJxqp8
} vAyFmdJ^
catch(Exception e){e.printStackTrace ();} CPNL 94x
} >3z5ww
} &u#&@J
pdE3r$C
?LvCR_D:
//打印回应的头信息 zZVfj:i8
public void logResponseHead(HttpURLConnection con) %Gt.m
{ J,Ks0MA
for(int i=1;;i++) LX^u_Iu
{ \&H nKhI
String header=con.getHeaderFieldKey(i); aN"DkUYZM
if(header!=null) /yM:|`tT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m1Y>Nj[f
Utility.log(header+" : "+con.getHeaderField(header)); um9_ru~
else T49zcJf;
break; g!-,]
} 4;2< ^[M
} o6V}$wT3J
H^YSJ6
oWYmj=D~2z
public void splitterStop() a'z)
{ +nJUFc
bStop = true; lo[.&GD
} foQ#a
r$2P;Cxj
AhZ8 0!
} N!g9*Z
tKpmm`2
o7|eMe?<t
/* ]xuG&O"SBV
**FileAccess.java 0qX3v<+[6
*//文件访问(定位，写) Th=eNL]
package NetFox; lV%N
import java.io.*; L'u\w
2Lx3=[ik
{)-aSywe
public class FileAccessI implements Serializable{ Uw47LP
~R(%D-k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /iX+R@
RandomAccessFile oSavedFile; V{JAB]?^
long nPos; 6L)%T02C
7}X[ 4("bB
3D2E?$dX
public FileAccessI() throws IOException U~pV)J
{ P>Ez'C
this("",0); J>\B`E
} 92EWIHEWZ
Z?\2F%
}mAa}{_
public FileAccessI(String sName,long nPos) throws IOException ~$~5qwl
{ p\<u6v ~J
oSavedFile = new RandomAccessFile(sName,"rw"); %"P,1&\^
this.nPos = nPos; Dc_yM
oSavedFile.seek(nPos); @;'o2
} 1PpyVf
qzTuxo0B
)a-Du$kd
public synchronized int write(byte[] b,int nStart,int nLen) "sG=wjcw^
{ E@ESl0a;
int n = -1; .FLy;_f+
try{ NUp<e%zB
oSavedFile.write(b,nStart,nLen); %@u;5qD&
n = nLen; Sv +IS
} OVV]x{
catch(IOException e) p>upA)W]
{ d!$Z(W0
e.printStackTrace (); 7k rUKYVo
} Z:*76PP,
<N%7|t*eT
#W|'1 OX4
return n; R=|{n'n$0|
} ;1a~pF S
!1ED~3/X
Z /9>
} C_7+a@?B
6b:tyQ
sJDas,7>
/* #Y4=J 6
**SiteInfoBean.java 1~PV[2a
*/ ~/P&Tub^
package NetFox; \ioH\9
{j7uv"|X7
^pYxKU_O
public class SiteInfoBean { 4y+< dw
`5C,N!d8X
Y 1t\iU
private String sSiteURL; //Site's URL Wr( y)D<y}
private String sFilePath; //Saved File's Path =17t- [
private String sFileName; //Saved File's Name D}mjN=Y
private int nSplitter; //Count of Splited Downloading File "OdXY"G
WS`qVL]^&
'L8' '(eZ^
public SiteInfoBean() R.yC(r
{//nSplitter的缺省值为5 i(NdGL#P
//default value of nSplitter is 5 fP. 6HF_p_
this("","","",5); zR{W?_cV
} 1A\OC
H(Z88.OM
MerFZd 1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Gy6l<:;
{ } x2DT8u
sSiteURL= sURL; fc |GArL#}
sFilePath = sPath; aL&n[
sFileName = sName; FGoy8+nB1M
this.nSplitter = nSpiltter; dzDqZQY$
sL\L"rQN6
fIsp;ca[k
} #n#@fAY
/|D*w^>
, T8>}U(
public String getSSiteURL() 6e[VgN-s
{ {\:{[{qF
return sSiteURL; D>LZP!
} ;<(W% _
sk=-M8;\
|v$JCU3!A
public void setSSiteURL(String value) H kQ)n3
{ TL}++e 7+
sSiteURL = value; (G[ *|6m
} TZY3tUx0|G
<OIIoB?t
dF2nEaN0%
public String getSFilePath() 4x 8)gE
{ |v({-*7
return sFilePath; /!3@]xz*
} PEW=@xj2y
'LE=6{#
`.i!NBA'6
public void setSFilePath(String value) a+%6B_|\
{ .%L?J E
sFilePath = value; jbS\vyG
} uA#P'?
z{o' G3
:gep:4&u
public String getSFileName() 2fWTY0
{ -(~!Jo_*'
return sFileName; "-vW,7y
} f PM8f
*U P@9D
EV*IoE$W]=
public void setSFileName(String value) _N{RVeO
{ @n{JM7ctJ
sFileName = value; [E/\#4b
} N-e @j4WU
[< &oF
a 0GpfW$t
public int getNSplitter() AMyIAZnYq)
{ B>0].CK`
return nSplitter; V{:A3C41
} USM4r!x
d~1gMz+)
mqSQL}vR
public void setNSplitter(int nCount) 4\4FolsK
{ lXjXqk\
nSplitter = nCount; ]Ccg`AR{
} 4UW_Do
} #0y)U;dA+w
XYZ4TeW\1
+O*/"]h
/* +7=K/[9p
**Utility.java z<##g
*/ mjKS{
package NetFox; fvdU`*|n)
B(n{e53 9f
hHT_V2*
public class Utility { z$?~Y(EY
k[:bQ)H
<U!`J[n%
public Utility() 4Za7^c.
{ 8&)DE@W
WRrd'{sB
vJ-q*qM1
} ~;#Y9>7\\'
6y9t(m
//线程睡眠 !g(KK|`,m
public static void sleep(int nSecond) QT>`^/]d
{ 98uV6b~g
try{ 2gCX}4^3b
Thread.sleep(nSecond); er!DYv
} DUC#NZgw
catch(Exception e) o1h={ao
{ .U?'i<
e.printStackTrace (); K0}pi+=
} cM$P`{QrM
} 8>WC5%f*
2&^]k`Aj6D
//日志 ihP|E,L=L
public static void log(String sMsg) YW60q0:
{ OeS\7
System.err.println(sMsg); ng_^
} y*tZ !m2Gg
C ihAU"
/p+>NZ"b
public static void log(int sMsg) ~1W x=
{ }}>q2y
System.err.println(sMsg); 32/MkuY^u
} DW_1,:,?7l
} }L#_\
r0,:J
BE_ay-
/* .7.b:Dn0
**TestMethod.java 9/ibWa\.
*/ r?Wk<>%>
package NetFox; .xH5fMj,"
83Q4On
RWgNo#<
public class TestMethod { k|lcc^[0
}DK7'K
znaUBv_
public TestMethod() [ji#U s:h
{ ///xx/weblogic60b2_win.exe b{]z wpf
try{ LS88.w\=S@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I/L_@X<*r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7w/4QiI
SiteFileFetch fileFetch = new SiteFileFetch(bean); pnbIiyV
fileFetch.start(); wT:b\km:!
} t-0a7 1#e
catch(Exception e){e.printStackTrace ();} -< &D
L&%s[
!VI]oRgP
} DIzH`|Y
b+&%1C
tjluk
public static void main(String[] args) A#95&kJpy
{ i*NH'o/
new TestMethod(); Y[K*57fs
} 8=Z9T<K
} "vyNxZE
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