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)); :X#'ELo|
} MK, $#
for(int i=0;i<nEndPos.length-1;i++) +ZPn[|
{ F!ra$5u
nEndPos = nStartPos[i+1]; E3h-?ugO'
} WlnS.P\+E
nEndPos[nEndPos.length-1] = nFileLength; j79$/ Ol
} JS0957K
} lxOUV?m^N
-^= JKd&p
hg}R(.1K=
//启动子线程 Z}$1~uyw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; l=^^l`
for(int i=0;i<nStartPos.length;i++) N##- vV
{ >D*%1LH~V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MGSD;Lgn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y_f^ dIK*=
nStartPos,nEndPos,i); &W-1W99auE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <=PYu:]h
fileSplitterFetch.start(); TDHS/"MbA7
} 4F?O5&329i
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jMQ7^(9-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kDK0L3}nr]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ky6 d{|H
nEndPos = " + nFileLength); 5:X^Q.f;
// fileSplitterFetch[nPos.length-1].start(); dZ'H'm;,!
BYWs\6vK
F}=O Mo:.
//等待子线程结束 R'p- 4
//int count = 0; !yf7y/qY
//是否结束while循环 }i@%$Ixsn
boolean breakWhile = false; Gque@u
$h8,QPy
lyQNE3
while(!bStop) WO"<s{v
{ L QA6iZBP
write_nPos(); 1|xo4fmV
Utility.sleep(500); JD{AwE@Ro
breakWhile = true; /7p1y v
F`JW&r\
m15> ^i^W
for(int i=0;i<nStartPos.length;i++) Dh B*k<S
{ )>8k8E
if(!fileSplitterFetch.bDownOver) 7xjihl3
{ Q(ec>+oi
breakWhile = false; `& }C*i"
break; d m$iiRY
} 3pI)
} geEETb}+y
if(breakWhile) "c0Nv8_G
break; yc3i> w`
I vD M2q8f
]:F?k#c
//count++; f^9ntos|
//if(count>4) pQ9~^
// siteStop(); `ls^fnJTpf
} 0%>_fMaA
5qQ\H}
A6%~+9
System.err.println("文件下载结束！"); C#D8 E.W
} :dj=kuUTbu
catch(Exception e){e.printStackTrace ();} /D ~UK"}
} _Q6` Wp6m
uT2w2A;
5R/k8UZ
//获得文件长度 H|/U0;s
public long getFileSize() %E`=c]!
{ Jw)-6WJ!uO
int nFileLength = -1; |g8Q.*"l[
try{ vN3uLz'<
URL url = new URL(siteInfoBean.getSSiteURL()); TC^fyxq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^)0b= (.
httpConnection.setRequestProperty("User-Agent","NetFox"); YKG}4{T
cy!;;bB
o`}(1$a>
int responseCode=httpConnection.getResponseCode(); g RBbL1
if(responseCode>=400) >\5IB5'j
{ {BS`v5*
processErrorCode(responseCode); +DA,|~k_
return -2; //-2 represent access is error ( t59SY
} -VhxnhS
ZIikDih1
".Sa[A;~
String sHeader; YB3?Ftgw
Nvj0MD{ X
l fJ lXD
for(int i=1;;i++) U((mOm6
{ fMZzR|_18
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LGPPyKNx
//Utility.log(in.readLine()); y?.l9
sHeader=httpConnection.getHeaderFieldKey(i); ^P}c0}^
if(sHeader!=null) ;LE9w^>^V
{ ~e#QAaXD#5
if(sHeader.equals("Content-Length")) Lm"zW>v
{ iK3gw<g
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WDq~mi
break; z`KP }-
} G+zIh}9
} w~l%xiC
else xI(Y}>
break; kH}HFl
} 3KN>t)A#
} &NB"[Mm:@
catch(IOException e){e.printStackTrace ();} 5;_&C=[
catch(Exception e){e.printStackTrace ();} ^U[yk'!Y
D~LU3#n
D|Raj\R
Utility.log(nFileLength); >{@:p`*
a<d$P*I(cH
n06Jg+
return nFileLength; 6qH^&O][
} 0$\ j
I!;vy/r
:]+p#l
//保存下载信息（文件指针位置） T f;:C]
private void write_nPos() !(>yB;u
{ cLyed3uU
try{ 32Jl|@8,g
output = new DataOutputStream(new FileOutputStream(tmpFile)); kQQhZ8Ch
output.writeInt(nStartPos.length); 0V5{:mzA
for(int i=0;i<nStartPos.length;i++) WSV[)-=:
{ Z|IFT1K
// output.writeLong(nPos); Sxg&73;ZV
output.writeLong(fileSplitterFetch.nStartPos); T,SCK^
output.writeLong(fileSplitterFetch.nEndPos); "pW@[2Dkx/
} ?Y|*EH
output.close(); !p$k<?WXc
} DX#_0-o
catch(IOException e){e.printStackTrace ();} }Asp=<kCc
catch(Exception e){e.printStackTrace ();} SlojB^%
} V07? sc<
JTI 'W
2z615?2_U
//读取保存的下载信息（文件指针位置） <N}*|z7=b
private void read_nPos() nk^-+olm
{ n9N'}z
try{ ZK8I f?SD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ct-;L' a
int nCount = input.readInt(); o; Ns-=
nStartPos = new long[nCount]; )'Yoii{dSU
nEndPos = new long[nCount]; y_A?}'X
for(int i=0;i<nStartPos.length;i++) nH -1,#`g
{ ]`GDZw`
nStartPos = input.readLong(); SdOE^_@:
nEndPos = input.readLong(); ?7CHHk
} sksop4gu5
input.close(); 2=p"%YSn
} g1zX^^nd,V
catch(IOException e){e.printStackTrace ();} qs'ggF1
catch(Exception e){e.printStackTrace ();} <;.->73E
} 2*1FW v
s#2<^6
qc6eqE
private void processErrorCode(int nErrorCode) jXALN
{ P<GHX~nB
System.err.println("Error Code : " + nErrorCode); 8 y+Nl&"V
} cgvD>VUw
<<:a>)6\
Gaxa~?ek
//停止文件下载 p-1 \4
public void siteStop() Up|>)WFw"
{ Jb4A!g5C
bStop = true; ?=X_a{}/
for(int i=0;i<nStartPos.length;i++) )ls<"WTC.
fileSplitterFetch.splitterStop(); d[Lr`=L;
G oJ\6&"
SXI3y
} YDMimis\H5
} <dA1n:3o
//负责部分文件的抓取 ;4rTm@6
**FileSplitterFetch.java OK"B`*
*/ r=3knCEWK
package NetFox; .0zNt
:x<'>)6
{Z=m5Dy}
import java.io.*; %95'oW)lo
import java.net.*; ]{<`W5b/
/kY|PY
F]SA1ry
public class FileSplitterFetch extends Thread { SdTJ?P+m
7>`VZ?
+#c3Y;JP
String sURL; //File URL ~yvOR`2Gg
long nStartPos; //File Snippet Start Position !7O!)WJ
long nEndPos; //File Snippet End Position tsA+B&R_]
int nThreadID; //Thread's ID "7k 82dw
boolean bDownOver = false; //Downing is over UHEn+Tc>
boolean bStop = false; //Stop identical M9/c8zZ
FileAccessI fileAccessI = null; //File Access interface a|x1aN0
d:"]*EZ [
ByK!r~>Z1Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]$>O--
{ PmGW\E[ni
this.sURL = sURL; H-sJt:
this.nStartPos = nStart; Q6G-`&5
this.nEndPos = nEnd; wf<=rW'
nThreadID = id; '$3]U5KOwK
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R{5xb
} bJo)rM:m
b$f@.L
|@x^5Ab$T
public void run() ]S6`",+)<f
{ {1Z`'.FU
while(nStartPos < nEndPos && !bStop) LH4!QDK-
{ +%'S>g0W=
q}PeXXH
G 1rsd
try{ c7[<X<yk
URL url = new URL(sURL); U9[ &ci
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gyak?.@R
httpConnection.setRequestProperty("User-Agent","NetFox"); 4E`y*Hmzy+
String sProperty = "bytes="+nStartPos+"-"; s0 ZF+6f
httpConnection.setRequestProperty("RANGE",sProperty); xm}9(EJ
Utility.log(sProperty); >[=fbL@N<@
Ny@CP}
RnN]m!"5
InputStream input = httpConnection.getInputStream(); [4NJ]r M%
//logResponseHead(httpConnection); pcd*K)
F_9eju^|
2g elmQnc
byte[] b = new byte[1024]; (5s$vcK
int nRead; 4LRrrW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v)*/E'Cr*
{ prvvr;Ib
nStartPos += fileAccessI.write(b,0,nRead); .{` :
//if(nThreadID == 1) "lcNjyU\O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }Km+5'G'U
} B>&Q]J+R
|gvx^)ro
@5!Mr5;
Utility.log("Thread " + nThreadID + " is over!"); #V[j Q Vl
bDownOver = true; g\CRx^s
//nPos = fileAccessI.write (b,0,nRead); mXd,{b'
} $4^cbk
catch(Exception e){e.printStackTrace ();} eSNwAExm
} 4l/hh|3@
} B{UL(6\B
OOzk@j^
{sn RS)-
//打印回应的头信息 WaY_{)x
public void logResponseHead(HttpURLConnection con) !_Z\K$Ns
{ dzIcX*"
for(int i=1;;i++) i6L>,^Dg
{ J*Dt\[X
String header=con.getHeaderFieldKey(i); /5qeNjI+2
if(header!=null) J#h2~Hz!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); YP*EDb?f
Utility.log(header+" : "+con.getHeaderField(header)); @>Y.s6a
else d5zv8?|X+
break; |'$E-[
} :fo.9J
} T5* t~`bfU
Wpgp YcPS
ETt7?,x@
public void splitterStop() !t.
{ 5Lmhip
bStop = true; #2`ST=#
} 4R 9lA
n}KF)W=
=<,>dBs}\
} ,"MRA
Z~&$s
F#0y0|
/* I4[sf
**FileAccess.java /y8=r"'G
*//文件访问(定位，写) C[E[|s*l
package NetFox; $ z4JUr!m
import java.io.*; s|p,UK
Ll" Kxg
VFmG\
public class FileAccessI implements Serializable{ <1t.f}}uX
vy:-a G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }XOTK^YA
RandomAccessFile oSavedFile; pr\wI?:k
long nPos; A_h|f5
gu~JB
OTgctw1s
public FileAccessI() throws IOException j ^Tb=
{ kn$2_I9
this("",0); _wp>AJ r
} 3shRrCL0mf
A_8UPGh8
U?@ s`.
public FileAccessI(String sName,long nPos) throws IOException r6JQRSakR
{ ;u:A:Y4V
oSavedFile = new RandomAccessFile(sName,"rw"); %S`ygc}|
this.nPos = nPos; DGc5Lol~
oSavedFile.seek(nPos); nj90`O.K
} ";kwh8wB
=d+~l
"YC5viX
public synchronized int write(byte[] b,int nStart,int nLen) be<7Vy]j
{ QPD[uJ(I
int n = -1; !iNN6-v%
try{ =&_Y=>rA]0
oSavedFile.write(b,nStart,nLen); #F|q->2`o
n = nLen; 0Z.X;1=
} )ajF ca@v
catch(IOException e) =<BPoGs5
{ {)CN.z:O
e.printStackTrace (); :@~Nszlb
} pW7#&@AR
>~F_/Z'5
De<kkR{4
return n; G?,b51"
} p2=+cS"HC
vkjHh.
y/.I<5+Bu
} C j4ED
'NAC4to;;
}J^+66{
/* ^~7/hm:
**SiteInfoBean.java JS!`eO/8
*/ V*I2
package NetFox; G m~2s;/
V[#$Sz[G
IaHu$` v
public class SiteInfoBean { Z,"f2UJ
:z^,>So:
I1)t1%6"vJ
private String sSiteURL; //Site's URL xf7_|l
private String sFilePath; //Saved File's Path }2]m]D@%7
private String sFileName; //Saved File's Name )*`cJ_t
private int nSplitter; //Count of Splited Downloading File %7v!aJ40
C}=9m A
">M:6\B
public SiteInfoBean() X(npgkVP\
{//nSplitter的缺省值为5 t%fcp
//default value of nSplitter is 5 th^&wp
this("","","",5); =M."^X
} #zed8I:w
dr gCr:Gf
B1k;!@@14
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e6i m_ Tk
{ PLueH/gC.
sSiteURL= sURL; MC~<jJ,
sFilePath = sPath; v\G+t2{
sFileName = sName; 0..]c-V(G
this.nSplitter = nSpiltter; ,382O$C
w{"ro~9o
"KKw\i
} =`OnFdI
8zrLl:{
*cy!PF&
public String getSSiteURL() r E&}B5PN=
{ v 8B4%1NE
return sSiteURL; ZkqZO#nq C
} X<<FS%:+
*q*$%H
y1bo28
public void setSSiteURL(String value) PlRcrT"#w
{ 6=p!`DOd
sSiteURL = value; Lk]W?
} .c]@xoC
jL0=a.;
"Ky&x$dje
public String getSFilePath() 5I&Dk4v
{ +QA|]Y~!
return sFilePath; V$g!#V
} w/@ tH
gq050Bl)
K$5mDScoJ
public void setSFilePath(String value) Z=s.`?Z
{ r\$`e7d}!
sFilePath = value; HrHtA]
} +Os9}uKf
\12y,fOJ
64t:
public String getSFileName() ?P(U/DS8
{ 8j}o\!H
return sFileName; U;LX"'}
} K1zH\wH
D(#6H~QN%
HEF\TH9
public void setSFileName(String value) QUWx\hqE
{ ?s[!JeUA
sFileName = value; -AwkP
} 'k/:3?R
];\XA;aOl}
GB}!7W"
public int getNSplitter() -V=,x3Zew
{ 6yd?xeD
return nSplitter; afd.v$63
} Qb'Q4@.
v;d3uunqv
7AQv4
public void setNSplitter(int nCount) 0](V@F"~
{ *|6*jU
nSplitter = nCount; Q$A;Fk}-
} qEM,~:lTn
} &<t`EI];)4
=h[;'v{
fHXz{,?/w
/* M2LW[z
**Utility.java LrdX^_,nt
*/ JsDT
package NetFox; T*92o:^
lKV7IoJ&;
Cw h[R
public class Utility { s"x(i
o^Qy71Uj
R*VEeLx
public Utility() Xw&vi\*m
{ =H?^G[y
1aoKf F(
F **/T
} }[]1`2qD
%9_jF"
//线程睡眠 L\\'n )
public static void sleep(int nSecond) `Wp y6o
{ 5E}!TL$
try{ U|v@v@IBA
Thread.sleep(nSecond); fDwqu.K
} @m9dB P
catch(Exception e) a@m 64l)
{ _vUId?9@+e
e.printStackTrace (); U[NQ"
} >z k6{kC
} RU\MT'E>(
9a]h;r8,9z
//日志 mg<S7+
public static void log(String sMsg) LcGG~P|ML
{ G1ED=N_#
System.err.println(sMsg); +d=8/3O%
} a~F\2`Q
nS]Ih0(K
O@-(fyG
public static void log(int sMsg) OD).kP}s^
{ i?6#>;f
System.err.println(sMsg); 4']eJ==OH
} 'y|p)r"
} _p0G8
/,JL \b
:@^T^
/* HlXEU$e
**TestMethod.java $pj;CoPm
*/ h:4F?'W
package NetFox; .`/6[Zp
}nMp.7b
-x+K#T0Z
public class TestMethod { @MfZP~T+
W4]jx]
~-#8j3 J;
public TestMethod() 0>U7]wZKc
{ ///xx/weblogic60b2_win.exe +}Qq#^:_\
try{ [wM]w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7?qRz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <O4W!UVg
SiteFileFetch fileFetch = new SiteFileFetch(bean); a+P^?N
fileFetch.start(); !z"nJC
} 3EA`]&d>
catch(Exception e){e.printStackTrace ();} @^,9O92l
|I s"ov
!^qpV7./l
} @@#(<[S\B
*iXaQuT
;f9a0Vs
public static void main(String[] args) f|&,SI?
{ D9higsN
new TestMethod(); 2t:CK
} HD;l1W)
} H1hADn
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