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)); 4jZt0
} jzDPn<WQ
for(int i=0;i<nEndPos.length-1;i++) Lp$&eROFVs
{ N|>MqH,Bt
nEndPos = nStartPos[i+1]; <LBCu;
} 5ip ZdQ^
nEndPos[nEndPos.length-1] = nFileLength; kp[&SKU c
} 7]L}~
} NPBOG1q%
',FVT4OMw
SP2";,%/9
//启动子线程 ;+f(1=x
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6tVp%@
for(int i=0;i<nStartPos.length;i++) e jk?If 07
{ :LX!T&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0[ n;ZL~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *yI((G/
nStartPos,nEndPos,i); _%rkN0-(a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E?K(MT&@
fileSplitterFetch.start(); tx1TtWo
} _pS)bxw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d<\X)-"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +BI%.A`2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5 YIk
nEndPos = " + nFileLength); <Vyl*a{%
// fileSplitterFetch[nPos.length-1].start(); /*S6/#
p0Ij4
'#lEUlB
//等待子线程结束 bsc b
//int count = 0; aFrZ ;_
//是否结束while循环 >>-{AR0
boolean breakWhile = false; W}(xE?9&
)u!}`UJ
yq[CA`zVN
while(!bStop) :oZ~&H5Q
{ 0#ePg6n
write_nPos(); `kOp9(Q{
Utility.sleep(500); i}:^<jDv?
breakWhile = true; ,+n{xI2
]tK<[8Y
gavf$be
for(int i=0;i<nStartPos.length;i++) V,tYqhQ3
{ w~9Y=|YI7
if(!fileSplitterFetch.bDownOver) [9CBTSr
{ 4%jSqT@
breakWhile = false; Z79Y$d>G<E
break; %.IW H9P7
} |oOA;JC)(
} pi*?fUg!W
if(breakWhile) [DSzhi]
break; J72kjj&C
]CnT4[f!
_B==S4^/yU
//count++; .YS48 c
//if(count>4) Bb5RZ#oa
// siteStop(); ^j_t{h)W(0
} :bp8S@
bb`DyUy ^+
ve/|"RB
System.err.println("文件下载结束！"); Z=s]@r
} #k)J);&ZA
catch(Exception e){e.printStackTrace ();} pvqbk2BO
} Q@l.p-:^U
2;ogkPv'
W2,Uw1\:1
//获得文件长度 wAF#N1-k
public long getFileSize() r$d'[ZcX
{ 6CWm;%B#G
int nFileLength = -1; R^4 j0L
try{ @JD!.3
URL url = new URL(siteInfoBean.getSSiteURL()); |Tl2r,(+R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6x_D0j%^]
httpConnection.setRequestProperty("User-Agent","NetFox"); !Ie={BpzbZ
SC0_ h(zb,
1,G f;mcQ
int responseCode=httpConnection.getResponseCode(); FVHR
if(responseCode>=400) DVyxe}
{ a*@4W3;7
processErrorCode(responseCode); /{X2:g{
return -2; //-2 represent access is error T 3+lYE
} pXxpEv
#J c)v0_
pB]+c%\
String sHeader; -+|{#cz
'%A*Z,f
!RdubM
for(int i=1;;i++) O:O +Q!58
{ u#34mg..
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v/7iu*u
//Utility.log(in.readLine()); F, p~O{ Q
sHeader=httpConnection.getHeaderFieldKey(i); dr7ry"5Zq
if(sHeader!=null) jP"='6Vrw
{ )VR/a
if(sHeader.equals("Content-Length")) W\yaovAt
{ >9]i#So^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >_?Waz%
break; (V+iJ_1g{
} +D+Rf,D
} :E9@9>3S
else k<NEauQ
break; 6Yx/m
} {f)"F;]V
} j%s:d(H`
catch(IOException e){e.printStackTrace ();} Kkds^v6
catch(Exception e){e.printStackTrace ();} rv97Wm+
{5gh.
-r"h[UV)
Utility.log(nFileLength); iYxpIqWw
5PCKBevV
gkDlh{
return nFileLength; _"%-=^_
} `~3y[j]kO
rwou[QU
sv?Lk4_
//保存下载信息（文件指针位置） js\|xfDxP
private void write_nPos() /F6=iHK(l
{ wi/dR}*A
try{ |d8x55dk
output = new DataOutputStream(new FileOutputStream(tmpFile)); :s OsG&y
output.writeInt(nStartPos.length); dg]: JU
for(int i=0;i<nStartPos.length;i++) mC(q8%/;
{ [8Zvs=1
// output.writeLong(nPos); S+(-k0
output.writeLong(fileSplitterFetch.nStartPos); Od:,r
output.writeLong(fileSplitterFetch.nEndPos); #\fxU:z~r
} v81H!c.*
output.close(); n$T'gX#5
} <U() *0
catch(IOException e){e.printStackTrace ();} CwVORf,uA
catch(Exception e){e.printStackTrace ();} 42: 6=\
} ;4 ON
9Iod[ x
]1 OZY@
//读取保存的下载信息（文件指针位置） nE3'm[)
private void read_nPos() S20L@e"U
{ `by\@xQ)
try{ 5b2_{6t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }[OOkYF#r
int nCount = input.readInt(); zLiFk<G@Xi
nStartPos = new long[nCount]; 7R=cxD&
nEndPos = new long[nCount]; -?$Hr\
for(int i=0;i<nStartPos.length;i++) kW@,P.88
{ qEoa%O
nStartPos = input.readLong(); ?xuhN G@
nEndPos = input.readLong(); #\]:lr{>?4
} }XiV$[xHd
input.close(); +5+?)8Ls
} n^AQ!wC
catch(IOException e){e.printStackTrace ();} 2& l~8,
catch(Exception e){e.printStackTrace ();} zLxO\R!d
} "NamP\hj
[nam H a
X_eh+>D
private void processErrorCode(int nErrorCode) 5 5_#?vw
{ }t[?g)"M#-
System.err.println("Error Code : " + nErrorCode); Y&Sk/8
} VY5/C;0^h
KPOr8=Rc
p=65L
//停止文件下载 !Z'x h +
public void siteStop() |h; _r&
{ dt(#|8i%
bStop = true; Rx22W:S=C.
for(int i=0;i<nStartPos.length;i++) Ok=RhoZZ
fileSplitterFetch.splitterStop(); CN$wlhs
ljij/C=
;r_YEPlZ
} 2R!1Vl
} l25E!E-'b
//负责部分文件的抓取 =;9*gDfD
**FileSplitterFetch.java n%>c4*t
*/ (gv1f
package NetFox; A@X&dy
.*N,x0B(
~EVD NnHEr
import java.io.*; a;Q.R
import java.net.*; q.l"Y#d
6mnj!p]3
z;_fO>u:
public class FileSplitterFetch extends Thread { D,rF?t>=S
L`$MOdF{_
^nYS@
String sURL; //File URL #mNM5(o
long nStartPos; //File Snippet Start Position i%8I (F
long nEndPos; //File Snippet End Position w>:~Ev]
int nThreadID; //Thread's ID RY(\/W#$
boolean bDownOver = false; //Downing is over MHv2r
boolean bStop = false; //Stop identical S'NZb!1+
FileAccessI fileAccessI = null; //File Access interface \)=X=yn2
yk4Huq&2
5{Xld,zw
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $Q[a^V~:
{ ^;b$`*M1
this.sURL = sURL; <wt#m`Za
this.nStartPos = nStart; #4ZDY,>Xi#
this.nEndPos = nEnd; t UJ m}+=>
nThreadID = id; s!Xj'H7K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U}55;4^LX
} J?WT
Z^w}: {
5h9`lS2
public void run() AS34yM(h
{ `,mE '3&
while(nStartPos < nEndPos && !bStop) MZGN,[~)6
{ {CM%QMM
c5?;^a[
p4 #U:_
try{ 7.n/W|\
URL url = new URL(sURL); sglYT!O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HB+\2jEE
httpConnection.setRequestProperty("User-Agent","NetFox"); mX)UoiXue
String sProperty = "bytes="+nStartPos+"-"; A#gmKS<J/7
httpConnection.setRequestProperty("RANGE",sProperty); \dAh^BK1(
Utility.log(sProperty); )&"l3*x
#<X+)B6t
U5; D'G
InputStream input = httpConnection.getInputStream(); OTA@4~{C
//logResponseHead(httpConnection); FnN@W^/z
85rXm*Df
e7f3dqn0
byte[] b = new byte[1024]; E?o1&(2p
int nRead; 28u)q2s^W|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N4$!V}pp
{ }[P1Va[!
nStartPos += fileAccessI.write(b,0,nRead); Ux~rBv''
//if(nThreadID == 1) 7(;M
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _L mDF8Q(
} X6jW mo8]
}yup`R
?*I2?
Utility.log("Thread " + nThreadID + " is over!"); PiMW29B^
bDownOver = true; PpPg ~ix*
//nPos = fileAccessI.write (b,0,nRead); )_P|_(
} sgdxr!1?y
catch(Exception e){e.printStackTrace ();} uV r6tb1
} }(h_ztw
} >t|u 8/P
=.9L/74@
Xqt3p6
//打印回应的头信息 uXiAN#1
public void logResponseHead(HttpURLConnection con) <StyO[
{ G992{B
for(int i=1;;i++) !/W[6'M#p
{ *ip2|2G$
String header=con.getHeaderFieldKey(i); 8=rD'*
if(header!=null) e_Na_l]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3 8>?Z]V
Utility.log(header+" : "+con.getHeaderField(header)); X/
else YGP.LR7
break; TAbd[:2{F
} ]sBSLEie '
} c:0nOP
) -+u8#
{_0m0 8
public void splitterStop() H#IJ&w|
{ `+_UG^aeW
bStop = true; -lr)z=})
} eMk?#&a)
D9 ~jMcX
rPVz!(;k
} p\]Mf#B
*NdSL
aZt5/|B
/* 8RJXY:%
**FileAccess.java 1 "'t5?XW
*//文件访问(定位，写) t|Cp<k]B
package NetFox; uGIA4CUm
import java.io.*; 1!,xB]v1Ri
3.M<ATe^
1Zc1CUMG
public class FileAccessI implements Serializable{ t#tAvwFM8
iR;Sd >)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6/`$Y!.ub
RandomAccessFile oSavedFile; rQ -pD
long nPos; (|DmYn!
S'>(4a
+cQGX5 K
public FileAccessI() throws IOException iHoQNog-!
{ hsIC5@s3
this("",0); X~ n=U4s}O
} $]IX11.m
4.|-?qG
<[O8{9j
public FileAccessI(String sName,long nPos) throws IOException QXZjsa_|
{ s`W\`w}
oSavedFile = new RandomAccessFile(sName,"rw"); CL{R.OA
this.nPos = nPos; J-t5kU;L{
oSavedFile.seek(nPos); KE3/sw0
} XQAdb"`
tZlz0BY!
*RugVH4
public synchronized int write(byte[] b,int nStart,int nLen) x/*ndH
{ 4.)hCb
int n = -1; !=j\pu} Z
try{ dI'cZt~n
oSavedFile.write(b,nStart,nLen); l:v:f@M&
n = nLen; G}1?lO_d`
} [t@
catch(IOException e) ~^*IP1.3
{ ?0_Bs4O\
e.printStackTrace (); 1vlRzkd
} N1rBpt
YEF|SEon0
_:ypPRJ
return n; R/8>^6
} U$o\?4
>%jQw.
d#yb($HAJ
} MxMrLiqU6l
/ sI0{
B0Ql1x#x
/* 2_@vSwC
**SiteInfoBean.java !e?;f=1+E
*/ EsR_J/:Qe
package NetFox; U 2k^X=yl
~A<1xszC
?3bUE\p
public class SiteInfoBean { S2nF13u
sM)qzO2wh
:#8#tLv
private String sSiteURL; //Site's URL ~~eR,HYk
private String sFilePath; //Saved File's Path Sc Uh -y_
private String sFileName; //Saved File's Name /Po't(-x
private int nSplitter; //Count of Splited Downloading File icW?a9b&
kfER
ld58R
public SiteInfoBean() f,GF3vu"
{//nSplitter的缺省值为5 L}O_1+b
//default value of nSplitter is 5 t}LV[bj1u
this("","","",5); 2\h]*x%:
} ~nk{\ rWO
S;DqM;Q
)-$Od2u2c
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9-)D"ZhLe
{ ]k~k6#),;
sSiteURL= sURL; <4,hrx&.
sFilePath = sPath; ,4$ZB(\
sFileName = sName; 9?c0cwP?
this.nSplitter = nSpiltter; tRU+6D <w
_[|~(lDJl
-V@vY42
} vZj:\geV
'PW~4f/m
(S/f!Dk&3
public String getSSiteURL() h$[}lZDg
{ NoS|lT
return sSiteURL; SP][xdN7
} K3jKOV8
] h3~>8<
,$irJz F
public void setSSiteURL(String value) rlSar$
{ JR/:XYS+
sSiteURL = value; b4`t, D
} lUWX[,
le%&r
r7w1~z
public String getSFilePath() n}?XFx!%
{ ~"eos~AuW
return sFilePath; \T)2J|mW
} G+Ft2/+\
A:$Qt%c
5Ug.J{d
public void setSFilePath(String value) df_hmkyj
{ X yi[z tN
sFilePath = value; JvFd2@
} LQT^1|nq
XB
@~pIyy\_
public String getSFileName() >Micc
{ QkbXm[K.Z
return sFileName; uan%j]|q%
} r}k2n s9
0k"n;:KM8
?@"F\Bv<h
public void setSFileName(String value) yPG,+uQ$.
{ wZ7Opm<nt
sFileName = value; _U}pdzX?
} A$gP: 1&m
px6[1'|g
6Y4sv5G
public int getNSplitter() $10"lM[
{ /VFh3n>I2
return nSplitter; S?pWxHR]
} olc7&R
0mcZe5RS
=6FA(R|QU
public void setNSplitter(int nCount) z~b5K\/1B
{ C3EQzr`
nSplitter = nCount; ktlI(#\%
} JJ\|FZN
} ]PWK^-4P
)kLTyx2&
W Z'UVUi8
/* \\Ps*HN
**Utility.java #R2wt7vE
*/ iTTUyftHT
package NetFox; lu~<pfg
JC|j*x(k/
W&E?#=*X
public class Utility { t>nx#ErS
9<qAf`
[n%=2*1p
public Utility() J~.8.]gXW
{ DIrQ5C
^0oOiZs
%K0 H?^.
} F@ Sw
FbH 1yz
//线程睡眠 DZPg|*KT
public static void sleep(int nSecond) \NE~k)`4j%
{ klkshlk d
try{ h-)tWJ c
Thread.sleep(nSecond); 'ii5pxeNI
} S\$=b_.
catch(Exception e) x-0O3IIE
{ tzH~[n,
e.printStackTrace (); pC=kvve
} WC2sRv4]3
} D^]g`V*N
.|ZO2MCd
//日志 IRWVoCc9/\
public static void log(String sMsg) p7H0|>
{ Sv&_LZ-"P
System.err.println(sMsg); =$kSvCjP
} D==C"}J
6ZvGD}/
v#/k`x\
public static void log(int sMsg) l1_hD,4
{ {lv@V*_Y0
System.err.println(sMsg); jU~q~e7Te
} L!/Zw~
} K+HP2|#6
)DR/Xu;b
<L!9as]w
/* -@=As00Bg
**TestMethod.java ~m`j=ot
*/ 42E%&DF
package NetFox; EV=/'f[++
&k\`!T1
Y)V)g9
public class TestMethod { |aD8
a]=k-Xh
%%uvia=e
public TestMethod() Veeuw
{ ///xx/weblogic60b2_win.exe ,> %=,x
try{ VD.wO%9?)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l$1 ]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5/w4[d
SiteFileFetch fileFetch = new SiteFileFetch(bean); 86 $88`/2
fileFetch.start(); <m"fzT<"
} zDD
catch(Exception e){e.printStackTrace ();} UnVYGch
NeI#gJ1A
>6X$iBb0
} JE~;gz]
~<.%sVwE
}0okyGg>q
public static void main(String[] args) lf`" (:./
{ obzdH:S
new TestMethod(); 7)-uYi] dA
} IjaFNZZC!
} |BA&ixHe~C
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