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)); lNo]]a+_
} gs(ZJO1 /L
for(int i=0;i<nEndPos.length-1;i++) Aj*|r
{ GGU>={D)
nEndPos = nStartPos[i+1]; f_z]kA +H
} !PfdY&.)
nEndPos[nEndPos.length-1] = nFileLength; Y;{(?0 s
} Y?V.O
} }BWT21'-Y
#'5{ ?Cb
629ogJo8
//启动子线程 (H;,E-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h,ipQ>
for(int i=0;i<nStartPos.length;i++) 8'Iei78Ov
{ &&7&/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M%bD7naBq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?h:xO\h8
nStartPos,nEndPos,i); mq+x=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {n{-5Y
fileSplitterFetch.start(); TR9dpt+T
} -VvN1G6.x?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r8>Qs RnU%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ub]s>aqy
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v$Xoxp
nEndPos = " + nFileLength); p^s:s-"f\
// fileSplitterFetch[nPos.length-1].start(); g'NR\<6A
l\37/Z
32p9(HQ
//等待子线程结束 ,rX|_4n*
//int count = 0; ~Kt2g\BSok
//是否结束while循环 <q`|,mc
boolean breakWhile = false; GsoD^mjY
V*W H
4t 0p!IxG
while(!bStop) M9.FtQhK/
{ ]VaMulb4
write_nPos(); Uka(Vr:
Utility.sleep(500); j/F:j5O*
breakWhile = true; sn8l3h)
Q>I7.c-M|
SM4'3d&mf
for(int i=0;i<nStartPos.length;i++) CQs,G8\/
{ p@eW*tE
if(!fileSplitterFetch.bDownOver) C,B{7s0-
{ qG3MyK%O\
breakWhile = false; <l<y R?
break; C6qGCzlG`
} i)(-Ad_
} HfEl TC:3f
if(breakWhile) +o]J0Gu
break; (gUVZeVFP
= O|}R
Yv3P]6c.
//count++; $ve*j=p
//if(count>4) ft$!u-`
// siteStop(); >]x%+@{|
} hX:yn:P~
aWY#gI{
k{ulu
System.err.println("文件下载结束！"); ]f6,4[
} [*g'Y;W
catch(Exception e){e.printStackTrace ();} _e "
} eC@b-q
xmejoOF
v?l*jr1-2
//获得文件长度 GQYB2{e>
public long getFileSize() w& )ApfL
{ i^)JxEPr w
int nFileLength = -1; 4MoxP
try{ mOJ-M@ME
URL url = new URL(siteInfoBean.getSSiteURL()); 4!A(7 s4t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 19i=kdH
httpConnection.setRequestProperty("User-Agent","NetFox"); 4$+/7I \
_sQhDi
or(P?Ro
int responseCode=httpConnection.getResponseCode(); qmtH0I7)
if(responseCode>=400) Y?%=6S
{ u179!
processErrorCode(responseCode); ]+Z,HY@;-
return -2; //-2 represent access is error >6|Xvtf
} %?J-0
:Aj[#4-=
'`&b1Rc
String sHeader; G@U}4'V9
91UC>]}H
$\L=RU!c}
for(int i=1;;i++) j07b!j:"\}
{ Ue=1NnRDkA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ->W rBO
//Utility.log(in.readLine()); L$?YbQo7
sHeader=httpConnection.getHeaderFieldKey(i); 0y%s\,PsT
if(sHeader!=null) S~B{G T\M
{ b@B\2BT
if(sHeader.equals("Content-Length")) |AS9^w
{ OpmPw4?}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OG^#e+
break; K<v:RbU|[1
} T+>W(w i
} [x0*x~1B
else w}U'>fj
break; WL;2&S/{@
} a[J_H$6H!
} `82^!7!
catch(IOException e){e.printStackTrace ();} "YN6o_*]
catch(Exception e){e.printStackTrace ();} LAuaowE\v
%Lom#:L'
o`nJJ:Cxq-
Utility.log(nFileLength); ]3 76F7
H<
:`S\p[5
return nFileLength; foe)_
} `~1#X
*LQt=~
e09QaY
//保存下载信息（文件指针位置） "sed{?
private void write_nPos() Bpv"qU7
{ gH0Rd WX
try{ [@0Hmd7
output = new DataOutputStream(new FileOutputStream(tmpFile)); EE*FvI`
output.writeInt(nStartPos.length); )H{OqZZYD
for(int i=0;i<nStartPos.length;i++) ;pG5zRe
{ *s?C\)x
// output.writeLong(nPos); yS4nB04`=
output.writeLong(fileSplitterFetch.nStartPos); `m\ ?gsw7
output.writeLong(fileSplitterFetch.nEndPos); %V92q0XW
} x) R4_3
output.close(); 2,p= %
} IeB^BD+j
catch(IOException e){e.printStackTrace ();} `eKFs0M.
catch(Exception e){e.printStackTrace ();} 33NzQb
} nM`pnR_
uk3PoB^>
q5.5%W
//读取保存的下载信息（文件指针位置） ^geY Ay
private void read_nPos() 5Z[HlN|-!
{ $SU<KNMZ
try{ 64SRW8AH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); zS `>65}e
int nCount = input.readInt(); >(W\Eh{J
nStartPos = new long[nCount]; *7C l1o
nEndPos = new long[nCount]; bK|nxL
for(int i=0;i<nStartPos.length;i++) ;JX2ebx
{ P?zL`czWd
nStartPos = input.readLong(); hYVy65Ea
nEndPos = input.readLong(); >|hqt8lY
} Agwl2AM5k
input.close(); Rc}#4pM8
} 3#idXc
catch(IOException e){e.printStackTrace ();} G$jw#a[L
catch(Exception e){e.printStackTrace ();} gh%Q9Ni-
} T8Ye+eP}
@Z89cTO
o3.b='HAm
private void processErrorCode(int nErrorCode) BUXlHh%<R
{ Xliw(B'\a4
System.err.println("Error Code : " + nErrorCode); 2`V(w[zTr
} 1Ch0O__2L
6t4{aa!L|9
aK8X,1g%)
//停止文件下载 I}\`l+
public void siteStop() lht :%Ts$
{ `91?^T;\F
bStop = true; l(~NpT{=V
for(int i=0;i<nStartPos.length;i++) C{YTHNn
fileSplitterFetch.splitterStop(); :(i=> ~O
XZxzw*Y1J
cB2~W%H
} ^F-AZP /5F
} Pa/2])w
//负责部分文件的抓取 Zrq\:KxX
**FileSplitterFetch.java nDXy$f8
*/ Suk;##I
package NetFox; |q 0iX2W
a'7RzN ,]
rM20Y(|
import java.io.*; h[gKyxZ/t
import java.net.*; / 16 r_l
9iGp0_J
)>!y7/3
public class FileSplitterFetch extends Thread { yXro6u?rC
r?WOum
8VMD304
String sURL; //File URL e_llW(*l8^
long nStartPos; //File Snippet Start Position #G("Oh
long nEndPos; //File Snippet End Position $3(E0\#O
int nThreadID; //Thread's ID y9K'(/
boolean bDownOver = false; //Downing is over /+f3jy:d
boolean bStop = false; //Stop identical .;37 e
FileAccessI fileAccessI = null; //File Access interface 3_Mynop
\5F {MBx !
U.J/ "}5`T
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8[u$CTl7a
{ SOvo%L@
this.sURL = sURL; UeaHH]U
this.nStartPos = nStart; _%<qZT
this.nEndPos = nEnd; j8?rMD~
nThreadID = id; Ki%RSW(_`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OZno 3Hn
} Edl .R}&1
zC!Pb{IaH
\C`2z]V%
public void run() t,qz%J&a
{ CPu~^ik
while(nStartPos < nEndPos && !bStop) `YK#m4gc
{ 0|~3\e/QV
OyyE0
?I 7hbqQd
try{ fUB+9G(Bx
URL url = new URL(sURL); Kk/cI6`W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \`YV)"y" ~
httpConnection.setRequestProperty("User-Agent","NetFox"); fCi1JH;
String sProperty = "bytes="+nStartPos+"-"; 0vcFX)]yW
httpConnection.setRequestProperty("RANGE",sProperty); Wp//SV
Utility.log(sProperty); \PK}4<x}
U_5\FM
E1>zKENN;
InputStream input = httpConnection.getInputStream(); &=laZxe
//logResponseHead(httpConnection); UvVq#<-
f/g-b]0
'];=1loD
byte[] b = new byte[1024]; Q}]RB$ZS
int nRead; kSO:xS0 _N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?^ `EI}g
{ Med0O~T%
nStartPos += fileAccessI.write(b,0,nRead); ?yAjxoE~?
//if(nThreadID == 1) yo#fJ`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {_X&{dZLX
} D<xDj#Z~1
G":u::hR
d7v_>
Utility.log("Thread " + nThreadID + " is over!"); \Gy+y`
bDownOver = true; 8#15*'Y
//nPos = fileAccessI.write (b,0,nRead); VY "i>Ae
} 79>_aD9
catch(Exception e){e.printStackTrace ();} CM+/.y T
} W. p'T}2
} tCr?!Y~
jUy$aGX
]f3R;d
//打印回应的头信息 KJ8Qi+cZ
public void logResponseHead(HttpURLConnection con) r<-@.$lf
{ :tBZu%N/N
for(int i=1;;i++) d]Mjr2h
{ _~uYNvmg
String header=con.getHeaderFieldKey(i); oCuKmK8
if(header!=null) G1/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aTPmW]w6
Utility.log(header+" : "+con.getHeaderField(header)); }G1hB#j
else XN~r d,MZ%
break; 5w@Q %'o`I
} 1fU~&?&-u
} };]f 3
4GqE%n+ta~
W>rx:O+
public void splitterStop() }B2qtb3
{ |BA<> WE
bStop = true; >y iE}
} kB;!EuL
of?0 y-LT%
X1Y+ao1)
} $Z4IPs
W&Kjh|[1QZ
1TL~I-G&n
/* N1u2=puJY
**FileAccess.java 3(>NS?lX
*//文件访问(定位，写) 'A9U[|
package NetFox; y7Y g$)sL
import java.io.*; '@eH)wh@m)
3dC;B@
kIYV%O
public class FileAccessI implements Serializable{ &p:GB_
nAW`G'V#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]LZ,>v
RandomAccessFile oSavedFile; I xE}v%&
long nPos; iU a `<
Ems0"e
2~2j?\AEd.
public FileAccessI() throws IOException FK.Qj P:
{ *p7_rY
this("",0); \x+"1
} ajALca4
{AMoE+U
M]M(E) *5
public FileAccessI(String sName,long nPos) throws IOException wT-@v,$
{ rgXD>yu(
oSavedFile = new RandomAccessFile(sName,"rw"); ^Ts8nOGMh
this.nPos = nPos; J9yB'yE8
oSavedFile.seek(nPos); ?u_O(eg
} #Vh$u%q3
~F=,)GE
odC}RdN
public synchronized int write(byte[] b,int nStart,int nLen) +a((,wAN2
{ #gY|T|
int n = -1; 0@dN$e
try{ 6i_dL|c
oSavedFile.write(b,nStart,nLen); ;B@-RfP
n = nLen; T&~7*j(|e
} xl;0&/7e
catch(IOException e) c %.vI
{ \h 1T/_4
e.printStackTrace (); MyJG2C#R
} 6pY<,7t0
Y'v;!11#
y]TNjLpo$
return n; 7H5t!yk|9
} <.B^\X$
Ug,23
zV"oB9\9O
} j9/Ev]im|F
B[nkE+s
om}jQJ]KH
/* N(BCe\FV
**SiteInfoBean.java `<^1Ik[g
*/ 3WQ"3^G
package NetFox; 2rJeON
bjYaJtn
Vm <9/UG<
public class SiteInfoBean { uw`fC%-xh
26<Wg7/,
W;@9x1jKX
private String sSiteURL; //Site's URL ,=Fn6'
private String sFilePath; //Saved File's Path ?sm@lDZ\
private String sFileName; //Saved File's Name S2*ER
private int nSplitter; //Count of Splited Downloading File auT'ATW7i
|=W=H6h*
s;4r)9Uvx
public SiteInfoBean() VPqMbr"L[
{//nSplitter的缺省值为5 zS+_6s
//default value of nSplitter is 5 R x.]m0
this("","","",5); {f<\`
} K JX@?1"
J,=: ]t
bD;c>5t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OlF5~VAbfb
{ K?:wX(JYT
sSiteURL= sURL; F_&bE@k
sFilePath = sPath; 0[T>UEI?
sFileName = sName; v5N2$Sqp*
this.nSplitter = nSpiltter; jwd{CN%
&9F(uk=X
T^~9'KDd
} {IpIQ-@l
e=%6\&q
`[zd
public String getSSiteURL() ]~A<Q{
{ ?Ok@1
return sSiteURL; 2?bE2^6
} +|=5zWI/
7yK1Q_XY>
wu2C!gyBo
public void setSSiteURL(String value) `Ufv,_n
{ Vdz(\-}ao
sSiteURL = value; #RA3 T[A
} qTl/bFD
U\\nSU
?dcR!-3
public String getSFilePath() q"Z!}^{
{ U DC>iHt
return sFilePath; mC}!;`$8p
} >7^+ag~&
r!7e:p JLO
/NDuAjp[@
public void setSFilePath(String value) [Ifhh2
{ 8xEOR!\!`k
sFilePath = value; ;y{VdT
} :9Vd=M6,
6b8@6;&LI
0piBK=tE/
public String getSFileName() X)TUKt
{ KZxA\,Y'5
return sFileName; _,i+gI[
} yw(E}
k v}<u
KtFxG6a
public void setSFileName(String value) !&Z,ev
{ U5z}i^8a
sFileName = value; {)vue0 vP
} Q$(0Nx<
n*oa J<o%
A'\jaB
public int getNSplitter() <XHS@|
{ "n3i(sZ
return nSplitter; ;5.o;|w?!
} aumXidbS
;|Z;YK@20
Q&9%XF uM
public void setNSplitter(int nCount) >Lo!8Hen
{ dWI.t1`i
nSplitter = nCount; OZ$"P<X_"
} ]%y~cq
} D-8>?`n\
BI\+NGrB
5w#*JK
/* '%m0@5|hCD
**Utility.java 7(<49bb.V
*/ =!#iC?I
package NetFox; 4#qjRmt
,ZYj8^gF
#89h}mp'
public class Utility { Bn"r;pqWiT
[wM<J$=2
m7XJe[O
public Utility() a#0GmK
{ /Jc?;@{
|m%M$^sZ}
QS~;C&1Hl
} ')9%eBaeK
@x@w<e%
//线程睡眠 ItTIU
public static void sleep(int nSecond) JL9d&7-
{ lbES9o5
try{ O^]I>A#d
Thread.sleep(nSecond); 8dw]i1t<
} TgaDzF,j{A
catch(Exception e) / -=(51}E
{ jz[|rwAp
e.printStackTrace (); lK^Q#td:`
} (jD..qMs#
} a.5s5g)8
T2wn!N?r
//日志 afEp4(X~
public static void log(String sMsg) W7as=+;X
{ -?b@6U
System.err.println(sMsg); >EMgP1
} 1q!JpC^
f=}Mr8W'
eh'mSf^=p
public static void log(int sMsg) /S;o2\
{ DJE/u qE
System.err.println(sMsg); wS2iyrIB
} >:]fN61#
} xQ7n$.?y@
,h2q37
We]X+>BlO
/* ~MY(6P
**TestMethod.java B-[SUmHr
*/ ;f-|rC_"
package NetFox; W4CI=94
$/C<^}A
71tMX[x
public class TestMethod { ]tZ5XS
h6x+.}}
81_3{OrE<
public TestMethod() D,eJR(5I
{ ///xx/weblogic60b2_win.exe Snt=Hil`
try{ H/V%DO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uz4mHyS6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .Qh8I+Q%
SiteFileFetch fileFetch = new SiteFileFetch(bean); dITnPb)i
fileFetch.start(); G 7)D+],{Y
} v%<_Mh
catch(Exception e){e.printStackTrace ();} fC3IxlG
s/[i>`g/9
0iXqAa
} =X X_Cnn
V8Q#%#)FHe
Kc udWW]
public static void main(String[] args) 8{+~3@T
{ @sKAsn
new TestMethod(); 16N8h]l
} `Ik}Xw
} 73~Mq7~8
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