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)); ;w+A38N$J
} Z2`e*c-[E
for(int i=0;i<nEndPos.length-1;i++) MJD4#G
{ NH?s
nEndPos = nStartPos[i+1]; :Ert57@l
} ~f@;.
nEndPos[nEndPos.length-1] = nFileLength; {<_}[} XY
} I{2e0
} zJV4)
~<$8i}7
G)putk@
//启动子线程 r&H>JCRZ<=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^]v}AEcmW
for(int i=0;i<nStartPos.length;i++) %] Bb;0G
{ i|=XW6J%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cvC;QRx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), IGp-`%9
nStartPos,nEndPos,i); :2?'mKa7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %TR->F
fileSplitterFetch.start(); 8"4`W~ 3
} H(g&+Wcu=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T"0a&.TLj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9!R!H&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f{+8]VA
nEndPos = " + nFileLength); $Qm;F% >
// fileSplitterFetch[nPos.length-1].start(); 10DS
%d=-<EQ|&
`P GWu1/
//等待子线程结束 Oa7W&wi
//int count = 0; M'g4alS
//是否结束while循环 (0k0gq;
boolean breakWhile = false; 'LX=yL]I
[2 Rp.?
crmnh4-
while(!bStop) S^n:O
{ wF&\@H
write_nPos(); z1"UF4x*
Utility.sleep(500); 8CYJR/
breakWhile = true; 4o|~KX8Qz
$4L=Dg
^L[Z+7|
for(int i=0;i<nStartPos.length;i++) jQ[Z*^"}
{ 7kb`o y;(^
if(!fileSplitterFetch.bDownOver) 5Ut0I]h|z
{ * T~sR'K+|
breakWhile = false; 'N}Wo}1r
break; 3$RII-}>
} 5= F-^
} u}$U|Cw-;T
if(breakWhile) nbYaYL?&
break; {b+IDq`)=
g_}@/5?y
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//count++; X!"y>J
//if(count>4) :q= XE$%H
// siteStop(); ,= PDL
} Mc\lzq8\ 1
&hF>}O
6Qo6T][
System.err.println("文件下载结束！"); iffU}ce
} E O}(MXS
catch(Exception e){e.printStackTrace ();} ^oP]@r"qy
} @emZwN"m
*yJb4uALB
gVuN a)
//获得文件长度 =CJs&Qa2
public long getFileSize() |, :(3Ml
{ Dp'/uCW)
int nFileLength = -1; [6D>2b}:{[
try{ t?{B*
URL url = new URL(siteInfoBean.getSSiteURL()); x^;nfqn|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JD>!3>S)?
httpConnection.setRequestProperty("User-Agent","NetFox"); |W::\yu6
+\E\&^ZQ
Oc8+an1m
int responseCode=httpConnection.getResponseCode(); ?W|POk}
if(responseCode>=400) 1ri#hm0x\
{ &iSQ2a!l8b
processErrorCode(responseCode); Wd%j;glG
return -2; //-2 represent access is error h&Sl8$jVp
} >LNl8X:Cz*
FKzqJwT
T<ua0;7
String sHeader; D2hvf^g'*
AfY(+w6!K
:@p`E}1r{
for(int i=1;;i++) !cq4+0{O;&
{ Sj*H4ZHD<&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <^&'r5H
//Utility.log(in.readLine()); sO*6F`eiZ
sHeader=httpConnection.getHeaderFieldKey(i); HY42G#^
if(sHeader!=null) @<AIPla
{ '|+_~ZO*d
if(sHeader.equals("Content-Length")) SY{J
{ mHhm~u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]A\n>Z!;
break; K;Xn!:) V:
} E6G^?k~q
} {7;TQ?/
else :DZiDJ@
break; 6?Wsg`9
} fY `A
} 6v1j*'
catch(IOException e){e.printStackTrace ();} FX'W%_f,
catch(Exception e){e.printStackTrace ();} Nn^el'S'
PF+`3
a#{a{>
Utility.log(nFileLength); ;J_d%
J)(pGS@
B[*i}k%i
return nFileLength; c9& 8kq5
} RXP"v-
\K4m~e@!
Z`f _e?
//保存下载信息（文件指针位置） ^hgpeu
private void write_nPos() 9hq7:
{ 0 Hq$h
try{ 9 (&!>z
output = new DataOutputStream(new FileOutputStream(tmpFile)); kfHLjr.
output.writeInt(nStartPos.length); Oll\T GXP!
for(int i=0;i<nStartPos.length;i++) VOiphw`
{ /q^( uWu
// output.writeLong(nPos); ;xRyONt
output.writeLong(fileSplitterFetch.nStartPos); 9DT}sCLz:B
output.writeLong(fileSplitterFetch.nEndPos); d EXw=u
} zL{KK9Or
output.close(); kn<[v;+
} ~jPe9
catch(IOException e){e.printStackTrace ();} =*'`\}];"
catch(Exception e){e.printStackTrace ();} M\GS&K$lq
} $pD^O!I)?
FYi<+]HZ
eD/?$@y
//读取保存的下载信息（文件指针位置） ;CC[>
private void read_nPos() 8?(4E 'vf
{ }{ P}P}
try{ Rw7Q[I5z%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w?R6$n`
int nCount = input.readInt(); 4f1*?HX&
nStartPos = new long[nCount]; !nd*U}q
nEndPos = new long[nCount]; 2{%BQq>C
for(int i=0;i<nStartPos.length;i++) 3sL#_@+yz
{ [~;9Mi.XL
nStartPos = input.readLong(); U@*z#T#"m
nEndPos = input.readLong(); Ufk7%`
} *s/F4?*
input.close(); d2(n3Xf
} 2 o.Mh/D0
catch(IOException e){e.printStackTrace ();} KSexG:Xb
catch(Exception e){e.printStackTrace ();} $`riB$v
} yK{~
P--#5W;^oB
0 8U:{LL
private void processErrorCode(int nErrorCode) 7<) .luV
{ QM$?}>:
System.err.println("Error Code : " + nErrorCode); @U9ov >E
} m/{rmtA4
w,P2_xk`
:8rqTBa`
//停止文件下载 'tdjPdw
public void siteStop() >Qi2;t~G
{ N_T;&wibO
bStop = true; Z$@Juv&>5^
for(int i=0;i<nStartPos.length;i++) U2h?l `nP
fileSplitterFetch.splitterStop(); LsmC/+7r$1
YS/DIH{9e
<?I~ +
} 1M+mH#?
} ^,rbA>/L
//负责部分文件的抓取 m!PN1$9V
**FileSplitterFetch.java |+[bKqI5
*/ 5bAy@n
package NetFox; !W6]+
u=4tW:W,
BeVQ[
import java.io.*; a~{mRh
import java.net.*; N". af)5
9iv!+(ni
kmuF*0Bjk
public class FileSplitterFetch extends Thread { g.veHh|;_
w+JDu_9+A]
KI#hII[Q.
String sURL; //File URL .-o$IQsS
long nStartPos; //File Snippet Start Position :_vf1>[
long nEndPos; //File Snippet End Position g{i(4DHm(
int nThreadID; //Thread's ID 5` Q#2
boolean bDownOver = false; //Downing is over }96^OQPE
boolean bStop = false; //Stop identical Q2+e`
FileAccessI fileAccessI = null; //File Access interface 1|Fukx<@J<
? 1_*ct=g9
l.&6|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jPFA\$To
{ 9_&.G4%V
this.sURL = sURL; QYg2'`(
this.nStartPos = nStart; x=9drKIw>
this.nEndPos = nEnd; B>JRta;hj
nThreadID = id; iptzVr#b[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X)'uTf0
} C7nLa@
i5rAb<q`
g4U%(3,>D
public void run() }PoB`H'K5
{ G"C'/
while(nStartPos < nEndPos && !bStop) o8Tt|Lxb$8
{ .)Du ;
&'i>5Y
6)Kg!.n%f
try{ /9i2@#J}W1
URL url = new URL(sURL); 38rC; 6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?*Jv&f#
httpConnection.setRequestProperty("User-Agent","NetFox"); &,bJ]J)8O
String sProperty = "bytes="+nStartPos+"-"; 2'N%KKmJL
httpConnection.setRequestProperty("RANGE",sProperty); B1\}'g8%f
Utility.log(sProperty); Yz[^?M%(D
3>-^/
}]/"auk
InputStream input = httpConnection.getInputStream(); n)[{nkS6[
//logResponseHead(httpConnection); )f,iey\-
}+,;wj~
0>>tdd7
byte[] b = new byte[1024]; ](B+ilr
int nRead; >NK*$r8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kJ{X5&,_
{ EQMn'>
nStartPos += fileAccessI.write(b,0,nRead); %[5hTf
//if(nThreadID == 1) <kp?*xV]]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V|DAw[!6N
} iz&)FuOr
EW|bs#l
QYDSE
Utility.log("Thread " + nThreadID + " is over!"); fyh9U_M);w
bDownOver = true; |&3[YZY
//nPos = fileAccessI.write (b,0,nRead); y&UcTE2;%(
} N<9CV!_
catch(Exception e){e.printStackTrace ();} R9^Vk*`gFU
} RYy_Ppn96f
} +AO(e
A-qdTJP
pm@Mlwg`1
//打印回应的头信息 zcy!YB
public void logResponseHead(HttpURLConnection con) >]s|'HTxF
{ QT&2&#Z
for(int i=1;;i++) +q6/'ErN]m
{ A+_361KH
String header=con.getHeaderFieldKey(i); GMrjZ
if(header!=null) B&VruOP0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~4<xTP\*
Utility.log(header+" : "+con.getHeaderField(header)); >2tYw,m
else !T!U@e=u
break; xhWWl(r`5
} u%}zLwMH
} srLXwoN[
F8S% \i
+coVE^/w
public void splitterStop() .]JGCTB3
{ tDJtsOL
bStop = true; TY"8.vd
} `O5wM\Z
[RoOc)u
VG_ PBG(
} AAb3Jf`UW
*2P%731n5
;p)RMRMg
/* 3MH9%*w'0
**FileAccess.java Zi/tax9C
*//文件访问(定位，写) u$O` \=
package NetFox; *c3(,Bmw
import java.io.*; 5_!s\5
ltK\)L
H,u{zU')
public class FileAccessI implements Serializable{ }>]V_}h
P%2aOsD0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8iA[w-Pv
RandomAccessFile oSavedFile; d|;S4m`
long nPos; 0%&ZR=y(G
B]iPixA6
piULIZ0
public FileAccessI() throws IOException n@[_lNa4GD
{ Se{x-vn?p
this("",0); z@Pv~"
} l|RBO+}
KPHtD4
K2|2Ks_CS
public FileAccessI(String sName,long nPos) throws IOException |qm_ESzl
{ =HapCmrx8
oSavedFile = new RandomAccessFile(sName,"rw"); ZRHK?wg'#
this.nPos = nPos; &6wD
oSavedFile.seek(nPos); =p{55dR
} Pu>jECcz
>>bsr#aJ
![1+=F!
public synchronized int write(byte[] b,int nStart,int nLen) 'o}v{f
{ wIQ~a
int n = -1; _@2}zT
try{ !>RDHu2n
oSavedFile.write(b,nStart,nLen); 71b0MHNkvv
n = nLen; JPO'1D)
} .Q!_.LX
catch(IOException e) EmG':K(
{ &tVIl$e
e.printStackTrace (); 2S,N9(7
} RRRF/Z;))
!B|Aq- n,
v'RpsCov
return n; w2X0.2)P2
} /{Mo'.=Z
03pD<
3']a1\sy^
} <$z6:4uN_
W>#[a %R
# RoJD:9
/* NVnId p
**SiteInfoBean.java L!;"73,&(8
*/ r+:]lO
package NetFox; C GN=kQ
;*u"hIl1/
I-Q@v`
public class SiteInfoBean { wE3L,yx=
WwUhwY1o!L
PaD6||1F
private String sSiteURL; //Site's URL (fA>@5n
private String sFilePath; //Saved File's Path /aTW X
private String sFileName; //Saved File's Name eR3v=Q
private int nSplitter; //Count of Splited Downloading File kI?+\k\V`
u*}ltR~/
YuXCRw9p;
public SiteInfoBean() <?Ln`,Duk
{//nSplitter的缺省值为5 pl}nbY
//default value of nSplitter is 5 pq"Z,9,F%
this("","","",5); zEVQ[y6BcM
} zsM2R"[X
%8O1sF
W{RZ@3ZY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #Mw 6>5}<
{ 22OfbwCb
sSiteURL= sURL; q\pI&B
sFilePath = sPath; 6b2Z}B
sFileName = sName; |`|#-xu
this.nSplitter = nSpiltter; %?`O .W
tgyW:<iv
fZ aTckbE
} _lG|t6y
gU&y5s~
LwlO)|E
public String getSSiteURL() ]z#+3DaH
{ K<rv|bJ
return sSiteURL; $-)T
} _`I}"`2H
>^6|^rc
l|81_BC"
public void setSSiteURL(String value) ;FGS(.mjlC
{ c>Tf@Aog>
sSiteURL = value; UY6aD~tD0
} 2U|"]tpM&
3qW](
$l $p|
public String getSFilePath() 38 ]}+Bb
{ Q7.jSL6
return sFilePath; s\zY^(v4
} =X1oB,W{
z]2MR2W@X
" Tk,
public void setSFilePath(String value) G|oO
{ G} f9:G
sFilePath = value; O3V.4tp
} ZO!h!2*
(%c&Km7K
Gf +>AjU'
public String getSFileName() 4bCA"QM[[
{ 4_D *xW
return sFileName; )&DsRA7v
} {,!!jeOO
-{}(U
]=o1to-
public void setSFileName(String value) L+mE&
{ 6FYL},.R
sFileName = value; &OlX CxH
} /lC,5y
/mA\)TL|]
-^)<FY\
public int getNSplitter() <&^[?FdAa
{ Im?/#tX
return nSplitter; k8\KCKql
} 3@nIoN'z
Q<NQ9lX
]4ck)zlv
public void setNSplitter(int nCount) M]|]b-#
{ Y<IuwS
nSplitter = nCount; Ee_?aG e&
} /6rQ.+|).
} h<V,0sZ&:
o|u4C{j
G1-r$7\
/* IL:[0q
**Utility.java Oq$-*N
*/ 6.9C4
package NetFox; d~MY z6"
|"PS e~ u
S}fQis
public class Utility { !?R#e`}
k`o8(zPb
:_<&LO]Q
public Utility() H | C3{9
{ 3dz{"hV
rb}fP #j
fWC(L s
} +PnuWK$
7Vk9{x$z
//线程睡眠 UD8e,/
public static void sleep(int nSecond) ]#[4eaCg
{ |)xWQ KzA
try{ E2 FnC}#W
Thread.sleep(nSecond); $vK,Gugcx
} _X
catch(Exception e) .Tm.M7
{ rg;4INs#
e.printStackTrace (); 8bQXC+bK
} [m4M#Lg\0
} Ie K+
@{UUB=}9
//日志 Tay$::V
public static void log(String sMsg) ~9OZRt[&
{ ]8R@2L3s
System.err.println(sMsg); bHcBjk.\
} 1;KJUf[N
U.V/JbXX
3#x1(+c6
public static void log(int sMsg) m]*a;a'}#
{ Niu |M@
System.err.println(sMsg); N p*T[J
} vz#-uw,O:
} .%dGSDru
Lagk
l]~9BPsR
/* n!AW9]
**TestMethod.java -T;^T1
*/ Q=>5@sZB
package NetFox; k q]E@tE*3
{]U \HE1w
[3sZ=)G
public class TestMethod { E<}sGzMc
00'SceL=`
~(^pGL3<
public TestMethod() 6;\1bP?
{ ///xx/weblogic60b2_win.exe 0Gc:+c7{
try{ YM#MfL#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); wfe4b
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w N`Njm9!
SiteFileFetch fileFetch = new SiteFileFetch(bean); FfxD=\
fileFetch.start(); &SPY'GQ!
} pH.&C 5kA
catch(Exception e){e.printStackTrace ();} i-;#FT+Xc
Cg?Mk6i
M%la@2SK=
} @)0
-9.lFuI
$j(d`@.DN~
public static void main(String[] args) hr&&b3W3p
{ T)%6"rPL3!
new TestMethod(); <,0/BMz
} v&(=^A\eN
} >&:}L%
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