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)); zU>bT20x/
} 8x6{[Tx
for(int i=0;i<nEndPos.length-1;i++) ViG-tb
{ =$%_asQJ
nEndPos = nStartPos[i+1]; \o!B:Vb<
} cp 7;~i3
nEndPos[nEndPos.length-1] = nFileLength; EG!):P
} 771r(X?Fa
} C'0=eel[
}D#[yE,=\
q}7(w$&
//启动子线程 fL R.2vJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; U[l{cRT
for(int i=0;i<nStartPos.length;i++) Z|Xv_Xo|4
{ `lq[6[n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yNmzRH u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q\v^3u2;m`
nStartPos,nEndPos,i); @$d_JwI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c:z<8#A}
fileSplitterFetch.start(); q0]Z` <w
} *6*/kV?F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p[gq^5WuC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J|I&{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e;)&Hc:Z
nEndPos = " + nFileLength); ,n+~S^r
// fileSplitterFetch[nPos.length-1].start(); ,1-#Z"~c
SSI('6Z/
#kDJ>r |&-
//等待子线程结束 ,!g%`@u
//int count = 0; <)9E.h
//是否结束while循环 <q#/z&F!
boolean breakWhile = false; ?f[U8S}
O0#9D'{
~f>km|Q{u
while(!bStop) < {dV=
{ @8GW?R
write_nPos(); 5l(Q#pSX
Utility.sleep(500); O_wRI\!
breakWhile = true; :>otlI<0t
q'awV5y
(!`]S>_w9
for(int i=0;i<nStartPos.length;i++) #AUz.WHD
{ v/lQ5R1
if(!fileSplitterFetch.bDownOver) B&)o:P7h
{ !;^TW$ G
breakWhile = false; %]i("21
break; UKxeN[fv
} >T~duwS
} -( ,iwFb
if(breakWhile) \a\ApD
break; JmK[7t
BPzlt
{]\!vG6
//count++; 14v,z;HXj
//if(count>4) =:-x;
// siteStop(); YV0K&d
} bfjtNF*^
BWN[>H %S
S7 Tem:/
System.err.println("文件下载结束！"); 2r=A'
} FO5'<G-
catch(Exception e){e.printStackTrace ();} !EQMTF=(
} v(tr:[V
<+c6CM$#}V
7&z`N^dz{
//获得文件长度 "ewB4F[
public long getFileSize() 9>"To
{ kdrya
int nFileLength = -1; f#9\&-he0
try{ 5#U*vGVT
URL url = new URL(siteInfoBean.getSSiteURL()); UF00K1dbz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,HQaS9vBQ
httpConnection.setRequestProperty("User-Agent","NetFox"); 0vRug|}k#%
aGz<Yip
qrmJJSJ
int responseCode=httpConnection.getResponseCode(); b 64~Y|8
if(responseCode>=400) l1qWl
{ =,=tSp
processErrorCode(responseCode); y$e'-v
return -2; //-2 represent access is error G_] (7
} oLXQ#{([
D'823,-).
CdRgI^5
String sHeader; c*g(R.!
]+B#SIC;
:8~*NSEFd
for(int i=1;;i++) 3[L)q2;}$N
{ &v^LxLt+s
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E}$K&<J'-
//Utility.log(in.readLine()); -l!;PV S|
sHeader=httpConnection.getHeaderFieldKey(i); QDC]g.x
if(sHeader!=null) >Cjb|f3'i}
{ @:s|X
if(sHeader.equals("Content-Length")) >aZ$x/U+Iw
{ QxmVImn"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FFNv'\)
break; |h,aV(Q
} 04wmN
} uz1t uX_
else W1s4[rL!Ht
break; m"!!)
} v?\bvg\E
} 5"[Qs|VjA6
catch(IOException e){e.printStackTrace ();} %@{);5[
catch(Exception e){e.printStackTrace ();} DaW_-:@s
UUx0#D/U0C
,z?Re)qm
Utility.log(nFileLength); 'lU9*e9
=B(zW.Gf
*p.P/w@1
return nFileLength; bqMoO7&c
} c4R6E~S
r)dT,X[}F
$ #C$V>
//保存下载信息（文件指针位置） @^vVou_
private void write_nPos() tF)aNtX4^
{ =^P<D&%q
try{ =J,aBp
output = new DataOutputStream(new FileOutputStream(tmpFile)); _AQ :<0/#
output.writeInt(nStartPos.length); ~h;c3#wuc
for(int i=0;i<nStartPos.length;i++) ^z$-NSlI
{ eA>O<Z1>
// output.writeLong(nPos); IiACr@[?e
output.writeLong(fileSplitterFetch.nStartPos); :Q\b$=,:
output.writeLong(fileSplitterFetch.nEndPos); Xv'M\T}6C+
} bf `4GD(
output.close(); b0i]T?#
} E#_TX3B
catch(IOException e){e.printStackTrace ();} )#r]x1[Kn
catch(Exception e){e.printStackTrace ();} GCx]VN3&
} o_<o8!]l"
#Vanw!
v.+-)RLQg
//读取保存的下载信息（文件指针位置） YSt']
private void read_nPos() ~_SV`io
{ Z8Fbx+~"
try{ LD WFc_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Da)[mxJ
int nCount = input.readInt(); CCX\"-C
nStartPos = new long[nCount]; [t /hjm"$
nEndPos = new long[nCount]; g[j"]~
for(int i=0;i<nStartPos.length;i++) :JSOj@s
{ m5sgcxt/
nStartPos = input.readLong(); +GWeu0b(~
nEndPos = input.readLong(); -lyT8qZ:(
} &gkloP@
input.close(); pd,5.d
} Gu&?Gn oc
catch(IOException e){e.printStackTrace ();} fw_V'l#\
catch(Exception e){e.printStackTrace ();} ^zQ;8)ng
} U]fE(mpI9
pHY~_^B4&
)[6H!y5
private void processErrorCode(int nErrorCode) z48,{H6h
{ v\t$. _at
System.err.println("Error Code : " + nErrorCode); LI?rz<H!D
} o\8yYX
0?ZJJdI3
_ 9Tv*@
//停止文件下载 <?,o {
public void siteStop() *;O$=PE
{ ;*+jCL2F
bStop = true; VZJs@qx:Z
for(int i=0;i<nStartPos.length;i++) |J2Rwf
fileSplitterFetch.splitterStop(); (hVhzw"~
CJ&0<Z}{m
l.lXto.6)
} gmWRw{nS+
} )2z (l-$.
//负责部分文件的抓取 VVvV]rU~
**FileSplitterFetch.java L!DP*XDp
*/ ?DkMzR)u
package NetFox; eQno]$-\
H__9%p#
~d7!)c`z
import java.io.*; [X=-x=S,
import java.net.*; w:&m_z#M
X#-U
AU$W=Z*
public class FileSplitterFetch extends Thread { &?/h#oF@\
%K /=7
k#ED#']N
String sURL; //File URL :sFP{rFx~
long nStartPos; //File Snippet Start Position RT8xU;
long nEndPos; //File Snippet End Position G1vWHa7n;f
int nThreadID; //Thread's ID mKPyM<Q
boolean bDownOver = false; //Downing is over L\5j"] }`
boolean bStop = false; //Stop identical Ezm ~SY
FileAccessI fileAccessI = null; //File Access interface 1/3Go97/qV
B+wSLi(
Io{)@H"f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .3A66 O~zT
{ Wj/.rG&tE
this.sURL = sURL; $k V^[
this.nStartPos = nStart; KDuM;
this.nEndPos = nEnd; ykxjT@[
nThreadID = id; ]0zXpMNI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?z171X0
} k(><kuJ`3
U"A]b(54
'AE)&56
public void run() r@H<@Vuc
{ ITRv^IlF
while(nStartPos < nEndPos && !bStop) iQZgs@
{ m]+g[L?-
Xp{+){Iu
"44VvpQC
try{ 0ho+Y@8
URL url = new URL(sURL); +%=Ao6/#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "CB*
httpConnection.setRequestProperty("User-Agent","NetFox"); @/ wJW``;
String sProperty = "bytes="+nStartPos+"-"; RN'|./N
httpConnection.setRequestProperty("RANGE",sProperty); M&~3fRb4
Utility.log(sProperty); lKrD.iYt8
OnC|9
]ZelB,7q
InputStream input = httpConnection.getInputStream(); amK?LDf]
//logResponseHead(httpConnection); Ajr]&H4
ce/Rzid
bPAp0}{Fu
byte[] b = new byte[1024]; xXE/pIXw
int nRead; PtCwr)B,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -wy$ ?Ha
{ k+{-iPm{
nStartPos += fileAccessI.write(b,0,nRead); 0iinr:=u
//if(nThreadID == 1) T/V8&'^i
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gdRwh
} ^TJn&k
Xlpu_H|
KRf$VbuL
Utility.log("Thread " + nThreadID + " is over!"); t]#y}V
bDownOver = true; x^qmYX$'1b
//nPos = fileAccessI.write (b,0,nRead); ><viJ$i
} WQ<J<$$uu
catch(Exception e){e.printStackTrace ();} { ,/mQ3
} 3 ~0Z.!O
} iJk`{P_
z[B*sbS
QDRSQ[\
//打印回应的头信息 ^!L'Aoy;E
public void logResponseHead(HttpURLConnection con) Ka&[ Oz<w
{ q%w\UAqA
for(int i=1;;i++) W^ict,t
{ nKp='>Th
String header=con.getHeaderFieldKey(i); Vz!W(+
if(header!=null) !krbGpTVH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ce\]o^4
Utility.log(header+" : "+con.getHeaderField(header)); p3`'i
else P}KN*Hn.
break; 5vj;lJKcd`
} iv2did4
} x'{L%c>L
)C5<puh
m:59f9WXA
public void splitterStop() :D8V*F6P
{ ='q:Io?T
bStop = true; k)UF.=$d
} %g{m12
w?d~c*4+
#:_qo
} ya0L8`q
!jL|HwlA
UB }n=
/* 8rAOs\ys
**FileAccess.java ^6bU4bA
*//文件访问(定位，写) 8bLA6qmM\
package NetFox; cu5Yvp
import java.io.*; "jH=O(37
OW-[#r
eEePK~%c
public class FileAccessI implements Serializable{ r t@Jw]az
fpJM)HU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vyP3]+n
RandomAccessFile oSavedFile; w>>)3:Ytd
long nPos; dR<sBYo
EYtf>D
w$WN` =
public FileAccessI() throws IOException 9"Oz-!Y4
{ lG/M%i
this("",0); G.OAzA13!t
} eVyXh>b*
wWv")dk3i
3JVENn9
public FileAccessI(String sName,long nPos) throws IOException T&c0j(
{ /L\]t
oSavedFile = new RandomAccessFile(sName,"rw"); =T;>$&qs
this.nPos = nPos; D0Yl?LU3
oSavedFile.seek(nPos); ^AkVmsv;;
} 0)`{]&
"K n JUXpl
HgPRz C
public synchronized int write(byte[] b,int nStart,int nLen) u@tJu'X
{ 6:O3>'n
int n = -1; j}7as&
try{ ||a 5)D
oSavedFile.write(b,nStart,nLen); dqMt6b\}
n = nLen; yBqv'Y
} P,r9<
catch(IOException e) y|f`sBMM
{ aG.j0`)%
e.printStackTrace (); 7p%W)=v
} knrR%e;
6FNs4|(d
++d(}^C;
return n; xdb9oH
} wNMgY
AuuZWd
<7N8L
} qR^KvAEQSo
DFKFsu8s
4A6D>ChB'E
/* Vw.c05x
**SiteInfoBean.java X~|P
*/ @FVan
package NetFox; ~WXT0-,
NSH20$A<
}_93}e
public class SiteInfoBean { B?`n@/
rqbX9M^
_9!*laR!2
private String sSiteURL; //Site's URL N=FU>qbz
private String sFilePath; //Saved File's Path p?(w!O
private String sFileName; //Saved File's Name Y^80@MJ
private int nSplitter; //Count of Splited Downloading File hT4u;3xE
gdkl,z3N3
q$FwO"dC
public SiteInfoBean() bh9rsRb}O
{//nSplitter的缺省值为5 k~f3~-"
//default value of nSplitter is 5 /+2;".
this("","","",5); &~VWh}=r
} ]vj4E"2;
q}gj.@Q"
fq(r,h=|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4Kjrk7GAx
{ vFz%#zk>
sSiteURL= sURL; e=K2]Y Q{
sFilePath = sPath; PkA_uDhw
sFileName = sName; gM_z`H5[!
this.nSplitter = nSpiltter; R\k= CoJJ
pwo5Ij,~q
?&#z3c$}
} -;pZC}Nd3
a)J3=Z-
#v!(uuq,
public String getSSiteURL() EOJk7
{ NX7(;02
return sSiteURL; lg` Qi&
} >;V ?s]
y,&.<Yc
b<,Z^Z_
public void setSSiteURL(String value) ]"bkB+I
{ jO xH'1I
sSiteURL = value; `L p3snS
} XQL"D)fw
#?%akQ+w
KWtLrZ(j
public String getSFilePath() .w5#V|
{ k8fvg4
return sFilePath; o=i)s2
} +E8\g
)6mx\t
n';"c;Ye)
public void setSFilePath(String value) -L e:%q2
{ 3=o^Vv
sFilePath = value; !z@QoD
} =f'MiU!p6
*zoAD|0N
Fx#0 :p
public String getSFileName() )=VSERs
{ K..L8#SC
return sFileName; )o!y7MTl
} 86Q\G.h7
}#~@HM>6Z
U-.?+`
public void setSFileName(String value) p&1IK8i"
{ v&g(6~b_>
sFileName = value; klHOAb1
} APxy%0Q
i! G^=N
vt{s"\f
public int getNSplitter() ;0*T7l
{ 9y=$|"<(
return nSplitter; K07SbL7g!p
} _nw=^zS
{SH+lX0]{
'VA\dpa{J
public void setNSplitter(int nCount) ,arFR'u>
{ }'HJVB_
nSplitter = nCount; w)I!q&`Y
} U9:?d>7
} z9mmZqhK\
~F7 +R
#PYTFB%
/* n]&/?6}
**Utility.java hpJ[VKe
*/ MGn:Gj"d
package NetFox; O+Z[bis`
9( ;lcOz
a<+Qw'
public class Utility { $<^4G
]'Y vI!r
0gNwC~IA8
public Utility() I}oxwc
{ [\N,ow,n
b 62 o
.<JD'%?"
} rAqg<fR*
(1e;7sNG@
//线程睡眠 + >o/Ob
public static void sleep(int nSecond) e-<fkU9^W
{ q4_&C&7
try{ ,ry2J,IT7
Thread.sleep(nSecond); x:8xGG9
} M7vc/E}]n
catch(Exception e) ,=KJ7zIK?
{ }N;c
e.printStackTrace (); :32
} M ,.++W\
} 9:0JWW^so
`o(PcX3/}
//日志 e9r#r~Qq|
public static void log(String sMsg) 2GRh8G&5
{ EgIFi{q=0
System.err.println(sMsg); xQs2)
} 2%g)0[1
@DK,ka(
eK\ O>
public static void log(int sMsg) 6L@g]f|Y@
{ =!3G,qV
System.err.println(sMsg); {UT>> *C
} $?p^ m`t_
} N>;"r]Rl"
$x;wnXXXM
,ZjbbBZ
/* rlu{C4l
**TestMethod.java {xr!H-9ZAA
*/ ^!^8]u<Q
package NetFox; `WF?87l1
mj :8ZZ
b\~rL,7(
public class TestMethod { qA:CV(Z
. (*V|&n
H~RWM'_
public TestMethod() 2&fIF}vk>m
{ ///xx/weblogic60b2_win.exe vW6Pf^yJ
try{ Vf6lu)Zc1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mJb>)bOl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pLMki=.Ld
SiteFileFetch fileFetch = new SiteFileFetch(bean); '/ 3..3k
fileFetch.start(); Uxx=$&#
} K'N`rx.7
catch(Exception e){e.printStackTrace ();} |;{^Mci%
c>d+q9M
`.nkC_d
} jeMh
#:L|-_=a
'7[{ISBXU
public static void main(String[] args) En3Q%
{ @TC_XU)&
new TestMethod(); YhFB*D;
} c_a*{L|c
} Bn*D<<{T
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