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)); :8\z 0
} 6fQQKM@a|
for(int i=0;i<nEndPos.length-1;i++) i!sKL%z}
{ 7e>n{rl
nEndPos = nStartPos[i+1]; r!j_KiUy
} :C>slxY
nEndPos[nEndPos.length-1] = nFileLength; D0tI
} 1^Ci$ra
} E3sl"d;~
Z*x Q"+\
.gx*gX1<
//启动子线程 p\F*Y,4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :/d#U:I
for(int i=0;i<nStartPos.length;i++) -bcm"(<T'
{ >*k3D&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yv]/A<gP+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), } n_9d.
nStartPos,nEndPos,i); qp'HRh@P2:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EXoT$Wt{$
fileSplitterFetch.start(); ocGqXDg3
} I`zn#U'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -hyY5!rD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); exZa:9 sp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7n}J}8Y*U2
nEndPos = " + nFileLength); YG!~v~sV
// fileSplitterFetch[nPos.length-1].start(); oTT/;~I
S'vrO}yU
->$Do$
//等待子线程结束 SUHyg/|F
//int count = 0; gQ/-.1Pz$
//是否结束while循环 )t&j0`Yq
boolean breakWhile = false; $oe:km1-D
R\ <HR9r
~ex1,J*}t
while(!bStop) E0Ig/ j
{ {3@/@jO?
write_nPos(); Gpo(Zf?
Utility.sleep(500); $hn#T#J3
breakWhile = true; 4*G#fW-
Z^>{bW
g]N!_Ib/!
for(int i=0;i<nStartPos.length;i++) .Hc]?R]
{ +Ae4LeVzc
if(!fileSplitterFetch.bDownOver) 349W0>eOT
{ #1&wfI$
breakWhile = false; GUJx?V/[
break; MG<F.u
} /87?U; |V
} yM=%a3
if(breakWhile) ,J!G-?:@n
break; fu"#C}{
q%2cx@c
&X }GJLC3
//count++; ~\6Kq`Y
//if(count>4) x?y)a9&Hm
// siteStop(); Myg &H(~
} hL+)XJu^J
bb}|"m.
:l'61$=
System.err.println("文件下载结束！"); ,n-M!y
} :Fm;0R@/k
catch(Exception e){e.printStackTrace ();} N/4`afiV.
} .|G([O^H
vB hpD
QcU&G*
//获得文件长度 u|BD=4*
public long getFileSize() !Z3iu
{ DwMq
int nFileLength = -1; /YKg.DA|
try{ [daUtKz
URL url = new URL(siteInfoBean.getSSiteURL()); x4r\cL1!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [>U'P1@ql
httpConnection.setRequestProperty("User-Agent","NetFox"); j;WZ[g#t
/2Y t\=S=
:&S6AP
int responseCode=httpConnection.getResponseCode(); Cd?aC
if(responseCode>=400) |$f.Qs~?
{ 9o@5:.b<j
processErrorCode(responseCode); >ZTRwy`_(
return -2; //-2 represent access is error XJ^dX]4
} ?>92OuG%W?
^7G@CBic"
f!|7j}3
String sHeader; 8' M43n
]DHB'NOh,
eG55[V<!
for(int i=1;;i++) kc Q~}uFB
{ |_xU{Pu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); k?zw4S
//Utility.log(in.readLine()); Oe:+%p
sHeader=httpConnection.getHeaderFieldKey(i); |08b=aR6ro
if(sHeader!=null) 1MkQ$v7m
{ p6VS<L
if(sHeader.equals("Content-Length")) Zi<Y?Vm/,O
{ zy^t95/m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ecfw[4B`
break; G~b/!clN
} o EXN$SIs
} 4! ]28[2B6
else 5?9K%x'b
break; TmZsC5
} |=&[sC
} ~4IkQ|,
catch(IOException e){e.printStackTrace ();} o/I'Qi$v-
catch(Exception e){e.printStackTrace ();} 6jyS]($q
Kx==vq%39
>c %*:a
Utility.log(nFileLength); >1q W*
'M8wjU
us%dw&
return nFileLength; 2l^hnog|
} T?B753I
0'j/ 9vm
-9W)|toWb"
//保存下载信息（文件指针位置） O~D>F*_^j
private void write_nPos() .K%1{`.|
{ Wwo'pke
try{ *i3\`;^=
output = new DataOutputStream(new FileOutputStream(tmpFile)); xvn@zi
output.writeInt(nStartPos.length); *|n-Hr
for(int i=0;i<nStartPos.length;i++) !:"$1kh1("
{ :E`/z@I
// output.writeLong(nPos); 4}-{sS}MP
output.writeLong(fileSplitterFetch.nStartPos); +||y/}1
output.writeLong(fileSplitterFetch.nEndPos); <~s{&cL!%#
} *f<+yF{=A
output.close(); Vcjmj
} r I)Y W0
catch(IOException e){e.printStackTrace ();} .xG3`YH
catch(Exception e){e.printStackTrace ();} t*J*?Ma
} K{DsGf,
sKDsps^$
K X0{dizZ
//读取保存的下载信息（文件指针位置） SWwL.-+E]
private void read_nPos() 9vX~gh{]~
{ $D&N^}alW
try{ F%|F-6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PiQsVk
int nCount = input.readInt(); my|]:(_0d
nStartPos = new long[nCount]; DD$YMM
nEndPos = new long[nCount]; F{,<6/ayRz
for(int i=0;i<nStartPos.length;i++) dZMf5=tb
{ `hpX97v
nStartPos = input.readLong(); :xwyE(w
nEndPos = input.readLong(); _TLB1T^/4
} ArK%?*`5
input.close(); KNvvYwFH]
} 0i|z$QRL~
catch(IOException e){e.printStackTrace ();} K9G1>*
catch(Exception e){e.printStackTrace ();} ZH<:g6
} oyfY>^bs
kz=Ql|@
ZRCm'p3
private void processErrorCode(int nErrorCode) )(CZK&<
{ kxvzAKz~
System.err.println("Error Code : " + nErrorCode); J]mG!#9
} yzI`&? P2
bn*SLWWQ.3
};/;L[,G
//停止文件下载 k{Ad(S4J&
public void siteStop() 4{zz-4=
{ kfc5ra>&
bStop = true; "2m (*+
for(int i=0;i<nStartPos.length;i++) OS- Xh-:z
fileSplitterFetch.splitterStop(); NQ&\t[R[
r.z=
~(v7:?
} c2E*A+V#u
} B:X,vE
//负责部分文件的抓取 =5l20 Um
**FileSplitterFetch.java \mo NpKf
*/ B r`a;yT
package NetFox; (D5sJ$&E@\
h&|PHI
Mn>/\e
import java.io.*; a%g|E'\Jw
import java.net.*; (i2R1HCa
uE'O}Y95
_ZMAlC*$G
public class FileSplitterFetch extends Thread { >(.GIR
e #!YdXSx
GBg~NkC7.
String sURL; //File URL C srxi'Pe
long nStartPos; //File Snippet Start Position NpPuh9e{
long nEndPos; //File Snippet End Position a*kvU"]
int nThreadID; //Thread's ID `AcUxnO
boolean bDownOver = false; //Downing is over #];b+ T
boolean bStop = false; //Stop identical XK+" x!
FileAccessI fileAccessI = null; //File Access interface Vd&&GI(:?^
Z~S%|{&Br
WPu-P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yw@kh^L
{ NNgpDL*
this.sURL = sURL; * a ?qV
this.nStartPos = nStart; |^09ny|
this.nEndPos = nEnd; s;!_'1pi@
nThreadID = id; R]LuZN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 fFe{oR
} C0`Bi:Ze
zhdS6Gk+
D\H;_k8
public void run() rWMG6+Scb
{ Q\moR^>
while(nStartPos < nEndPos && !bStop) {VmJVO]S
{ DWwPid} "
'W_u1l/
F$6JzF$|F
try{ ;udV"7C
URL url = new URL(sURL); ~[@gu,Wb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w\}@+w3b~
httpConnection.setRequestProperty("User-Agent","NetFox"); !'qY
String sProperty = "bytes="+nStartPos+"-"; %iq8dAW%
httpConnection.setRequestProperty("RANGE",sProperty); T1*%]6&V|
Utility.log(sProperty); &#< M o
G^%FP!'D?
G2y`yg
InputStream input = httpConnection.getInputStream(); ?h|&kRq
//logResponseHead(httpConnection); Kj{(jT
Hy~+|hLvh
B?gFFU61
byte[] b = new byte[1024]; @,^c?v
int nRead; $*')Sma
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o|cx?
{ DQI b57j
nStartPos += fileAccessI.write(b,0,nRead); ;R[w}#Sm
//if(nThreadID == 1) PP-U.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^&Vj m
} A)%!9i)
<y2HzBC
+5i~}Q!
Utility.log("Thread " + nThreadID + " is over!"); q@=3`yQ
bDownOver = true; e0:[,aF`
//nPos = fileAccessI.write (b,0,nRead); mDdL7I
} LX8A@Yct
catch(Exception e){e.printStackTrace ();} 259R5X<V
} +ktubJ@Qgj
} xP7#`S6W
)R^&u`k
nh'TyUd!
//打印回应的头信息 \=&F\EV
public void logResponseHead(HttpURLConnection con) M/a40uK
{ L/c`t7
for(int i=1;;i++) /6{P ?)]pE
{ aN?^vW<
String header=con.getHeaderFieldKey(i); ?RPVd8PUhN
if(header!=null) =1r!'<"h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +4g H=6
Utility.log(header+" : "+con.getHeaderField(header)); 90Bn}@t=Q
else <Toy8-kj
break; }h+{>{2j
} "$#<+H>O
} {2.zzev'
&V(;zy4(R
#ZyY(S1.
public void splitterStop() 34F;mr"yp
{ j"r7M|Z+V
bStop = true; !nDiAjj
} !O 0{ .k
],-(YPiAD
)}$]~ f4R
} 7h#*djef
2DNB?,uP,'
A}4 ",
/* x8!uI)#tS
**FileAccess.java lj /IN[U/
*//文件访问(定位，写) QAzwNXE+
package NetFox; D k<NlH zp
import java.io.*; c5(4rT{(m
rrP_7D
lBzfBmEB
public class FileAccessI implements Serializable{ 25Uw\rKeO
ER,!`C]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Vji:,k=3\
RandomAccessFile oSavedFile; |)*9BN
long nPos; {,B.OM)J
e<$s~ UXv
^{Fo,7
public FileAccessI() throws IOException }2hU7YWt
{ NjbIt=y
this("",0); 2jF}n*[OW
} 8ByNaXMO6
u<JkP <"S
x~QZVL=:
public FileAccessI(String sName,long nPos) throws IOException ntQW+!s;P
{ /:@)De(S
oSavedFile = new RandomAccessFile(sName,"rw"); 6~OJB!
this.nPos = nPos; kgHZaQnD
oSavedFile.seek(nPos); _BoYyJQH
} _<%YLv
/'a\$G"%6
w0X})&,{`m
public synchronized int write(byte[] b,int nStart,int nLen) FQ"ED:lks
{ 12@Ge]
int n = -1; ~gdnD4[G
try{ ?sv[vR(
oSavedFile.write(b,nStart,nLen); .hRtQU
n = nLen; Dkg^B@5Xr
} 9aBz%* xo
catch(IOException e) w>e+UW25Y
{ []G@l. ]W
e.printStackTrace (); Q7]bUPDO
} GuC 9h^[=M
M5:j)oW
~ycWcZi>
return n; 2f6BZ8H+Z
} BvS!P8
v7/k0D .
ZypK''&oc
} \M;cF"e-S
qpjiQ,\:b
O^n\lik
/* OX7a72z
**SiteInfoBean.java WmOu#5*;
*/ GX=U6n>
package NetFox; J"-/ok(<@
*v$j n
_*cKu>,O
public class SiteInfoBean { [A'e7Do%'
j\HZ5
#^tnRfS"
private String sSiteURL; //Site's URL %]1te*_
private String sFilePath; //Saved File's Path t&i4kS^y
private String sFileName; //Saved File's Name |\xTcS|d
private int nSplitter; //Count of Splited Downloading File Aho-\9/x%
mV0u:ws
7x]q>Y8T
public SiteInfoBean() r4ljA@L
{//nSplitter的缺省值为5 u2OrH3E4E3
//default value of nSplitter is 5 26p_fKY
this("","","",5); y@SI)&D
} ehLn+tg
-p"}K~lt:
X]D:vuB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a'g&1N0Rc
{ 'w=aLu5dY
sSiteURL= sURL; >2v<;.
sFilePath = sPath; X|yVRQ?F`
sFileName = sName; 6n|][! f
this.nSplitter = nSpiltter; _S,UpR~2W
Gx*B(t]4y
$b[Ha{9(v
} R8 LHwRQ
Jl1\*1"
yMD3h$w3a
public String getSSiteURL() CM6! 1 7
{ [{>3"XJ'
return sSiteURL; FOteNQTj
} \t%iUZ$
'#>Fe`[
`.Zm}'
public void setSSiteURL(String value) lavy?tFer
{ P@Fx6
sSiteURL = value; QX42^]({;c
} 2.^CIJc
CfVL'
&?TXsxf1Zh
public String getSFilePath() do9~#F
{ "Th;YJu
return sFilePath; m.<or?l'y>
} j{johV+`8
%<r}V<OeR
<m0=bm{j
public void setSFilePath(String value) @NL37C
{ 1!yd(p=cL
sFilePath = value; xLms|jS
} Xpv<v[a
-zWNQp$
$$SJLV
public String getSFileName() C$$Zwgy
{ RR|X4h0.
return sFileName; VrWQ]L
} QpA$='
#R7hk5/8n}
Q`{Vs:8X
public void setSFileName(String value) [e_<UF@A*
{ ?B@3A)a
sFileName = value; tvBLfqIr
} =*{7G*tS
C+>mehDC_G
s8'!1rHd
public int getNSplitter() R;fev 1mE
{ &gr T@
return nSplitter; s>1\bio*I
} .l|29{J
stMxlG"d
tc{l?7P
public void setNSplitter(int nCount) NJmx(!Xsh
{ vE1:;%Q
nSplitter = nCount; 45x4JG
} ROvY,-?
} ~*J <lln
kd_!S[
<f=<r*6
/* }gFa9M<
**Utility.java b4EUrSL
*/ Y+kuj],h
package NetFox; `t44.=%
;#+I"Ow
l>L?T#v!_
public class Utility { SL/'UoYm<
.Wr7*J[V.
!VXy67
public Utility() +Z-{6C
{ }2\Hg
LpI4R
%%I:L~c
} bKsEXS
`Y+R9bd
//线程睡眠 e@]m@
public static void sleep(int nSecond) &y7=tEV
{ p!)PbSw#
try{ 2pvby`P4
Thread.sleep(nSecond); :;TF_Sv
} /|#2ehE
catch(Exception e) U#- 5",X|
{ S6\E I5S
e.printStackTrace (); $=#Lf[|f=
} m-a':
} 1f1D^|
*3OlWnZ?
//日志 |'uBkL0q
public static void log(String sMsg) ueg%D+u
{ #T8jHnI
System.err.println(sMsg); 7h2/8YUgQ
} st~l||
^UhqV"[7k
$FDGHFM
public static void log(int sMsg) P #8+1iC1
{ R4'>5.M
System.err.println(sMsg); ("{vbs$;
} XD?]+
} s<Nw)Ynw
xls US'Eo
nr8#;D
/* ,aq>9\pi
**TestMethod.java +fKV/tSWi
*/ ;8 *"c
package NetFox; ;CoD5F!
__1Hx?f
\TnK<83
public class TestMethod { {X<_Y<
;Jb%2?+=!
PMX'vA`
public TestMethod() m(dW["8D
{ ///xx/weblogic60b2_win.exe fZS'e{V
try{ R?,v:S&i7;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ew~uOG+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6 {F#_.
SiteFileFetch fileFetch = new SiteFileFetch(bean); F&^&"(H}
fileFetch.start(); 1{RA\CF
} T~SkFZ
catch(Exception e){e.printStackTrace ();} %Wm)
(Rp5g}b
j9w{=( MV
} +W$uHQq
-UAMHd}4
8Fbt >-N<\
public static void main(String[] args) S$P=;#r
{ ;9-J=@KY4
new TestMethod(); BZKg:;9
} jq_4x[
} jeO`45O
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