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)); `O,"mm^@U
} 0c#|LF_
for(int i=0;i<nEndPos.length-1;i++) w4&-9[@Y
{ ,S3uY6,
nEndPos = nStartPos[i+1]; wlX K2D
} `\-mqe
nEndPos[nEndPos.length-1] = nFileLength; 28,HZaXhc
} 6;\Tps;A
} hcD.-(-;)
}Tk*?tYt
+Kg3qS"
//启动子线程 "8yDqm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k*T&>$k}^
for(int i=0;i<nStartPos.length;i++) hniTMO
{ qQ<7+z<4KP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]n|lHZR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), LTio^uH
nStartPos,nEndPos,i); y{qKb:~wv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qB=%8$J
fileSplitterFetch.start(); 7!, p,|K
} $5yH8JU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D|5Fo'O^AV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k$K>ml/h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YcuHYf5
nEndPos = " + nFileLength); Ils^t
// fileSplitterFetch[nPos.length-1].start(); )0@&pEObm
w3oe.hWP3N
{[FJkP2l
//等待子线程结束 8F`799[p
//int count = 0; R 9Yk9v
//是否结束while循环 yCye3z.
boolean breakWhile = false; \E:l E/y
2W`<P2IA
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while(!bStop) Q%RI;;YyA
{ WG*S:_?
write_nPos(); Q92hI"
Utility.sleep(500); Z|Xv_Xo|4
breakWhile = true; /T/7O
<3aW3i/jTc
!p"Ijz5
for(int i=0;i<nStartPos.length;i++) {nmBIk2v
{ [U?a %$G>
if(!fileSplitterFetch.bDownOver) lF1ieg"i M
{ 0f|nI8,z
breakWhile = false; ig,v6lqhM
break; $t$YdleIH
} bG9$&,
} E./Gt.Na
if(breakWhile) )SFyQ
break; \rf2Os
Dmv@ljwO
0_-NE4SM/
//count++; Q"an6ht|
//if(count>4) qw%wyj7
// siteStop(); 5oIgxy
} HvVS<Ke
@8GW?R
z}m)u
System.err.println("文件下载结束！"); Ni 5Su
} L%O( I
catch(Exception e){e.printStackTrace ();} oT27BK26?h
} p=U5qM.O
S~LTLv:>
o5eFLJ6
//获得文件长度 s;-%Dfn
public long getFileSize() \?.Tq24
{ /WKp\r(Hp
int nFileLength = -1; ~,.}@XlgT.
try{ #>\+6W17U
URL url = new URL(siteInfoBean.getSSiteURL()); v5o@ls
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VjVL/SO/
httpConnection.setRequestProperty("User-Agent","NetFox"); %7bZnK`C
LK[%}2me
<oWoJP`G
int responseCode=httpConnection.getResponseCode(); x?B8b-*
if(responseCode>=400) ?rgk
{ ^aG=vXK`b
processErrorCode(responseCode); gkyv[
return -2; //-2 represent access is error &-0eWwMW
} {$mj9?n=v
i.`RQZ$,/
#<|q4a{8
String sHeader; D#,P-0+%
^d2bl,1
T&`H )o
for(int i=1;;i++) C6C7*ks
{ "ewB4F[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q9&d24|
//Utility.log(in.readLine()); kdrya
sHeader=httpConnection.getHeaderFieldKey(i); M%8:
if(sHeader!=null) 5#U*vGVT
{ UF00K1dbz
if(sHeader.equals("Content-Length")) ,HQaS9vBQ
{ 0vRug|}k#%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aBLE:v
break; qrmJJSJ
} {r!X W
} <ZM8*bqi
else yr /p3ys
break; D 4\T`j:
} hD:$Sv/H
} G6b\4}E
catch(IOException e){e.printStackTrace ();} n3kYVAgF
catch(Exception e){e.printStackTrace ();} M6J/S
_ADK8a6%)
pPdOwK#
Utility.log(nFileLength); ~\z\f}w
LAwl9YnG:
"3i=kvdz
return nFileLength; L@{5:#-
} g2<xr;<t^
$iA`_H`W
v&EHp{8Qd
//保存下载信息（文件指针位置） *?`:=
private void write_nPos() G*|2qX"o
{ yU(k;A-
try{ YrR}55V,
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3'WS6B+
output.writeInt(nStartPos.length); e_BOzN~c
for(int i=0;i<nStartPos.length;i++) X192Lar
{ F_$K+6
// output.writeLong(nPos); v?7.)2XcX
output.writeLong(fileSplitterFetch.nStartPos); (Js'(tBhiU
output.writeLong(fileSplitterFetch.nEndPos); >_y>["u6J#
} %HJ_0qg
output.close(); N*Owfr1N
} WJ+<&6W8
catch(IOException e){e.printStackTrace ();} EK^ld!g(
catch(Exception e){e.printStackTrace ();} Q b5AQf30
} oh5fNx
=B(zW.Gf
l#,WMu&
//读取保存的下载信息（文件指针位置） uL!{xuN
private void read_nPos() hNV"{V3`{
{ GJA3
try{ ,OLN%2Sq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^AUmIyf_
int nCount = input.readInt(); [Uezi1I
nStartPos = new long[nCount]; pt;kN&A^
nEndPos = new long[nCount]; {}ZQK
for(int i=0;i<nStartPos.length;i++) m.MOn3n]
{ otXB:a
nStartPos = input.readLong(); (s,*soAN
nEndPos = input.readLong(); nJYcC"f
} ipEsR/O
input.close(); *fq=["O
} Ywf.,V
catch(IOException e){e.printStackTrace ();} |/g\N,]
catch(Exception e){e.printStackTrace ();} h!f7/)|[o
} j+n1k^jC
~<pGiW'w5
1X/ q7lR
private void processErrorCode(int nErrorCode) e/WR\B'1
{ J*8fGR%
System.err.println("Error Code : " + nErrorCode); i8nCTW
} $+sNjwv^F
N"b>]Ab] ;
M[0@3"}}
//停止文件下载 EM*YN=So
public void siteStop() Ftm%@S?
{ GCx]VN3&
bStop = true; ()vxTTa
for(int i=0;i<nStartPos.length;i++) v!ULErs
fileSplitterFetch.splitterStop(); v.+-)RLQg
74%,v|
~_SV`io
} Z8Fbx+~"
} LD WFc_
//负责部分文件的抓取 Da)[mxJ
**FileSplitterFetch.java CCX\"-C
*/ [t /hjm"$
package NetFox; g[j"]~
:JSOj@s
m5sgcxt/
import java.io.*; 16o3ER
import java.net.*; z@cL<.0CE
2-u>=r0L
QhK]>d.
public class FileSplitterFetch extends Thread { `,&h!h((
gydPy*
L&lNpMT
String sURL; //File URL i7})VDsZ
long nStartPos; //File Snippet Start Position !E> *Mn
long nEndPos; //File Snippet End Position ;y?,myO
int nThreadID; //Thread's ID jj#K[@u
boolean bDownOver = false; //Downing is over i 4eb\j
boolean bStop = false; //Stop identical 1P4jdp=~
FileAccessI fileAccessI = null; //File Access interface >(u=/pp=:
A%u-6"
S 1|[}nYP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j ij:}.d6
{ =_8
this.sURL = sURL; k:<yy^g$X
this.nStartPos = nStart; "-vm=d~\
this.nEndPos = nEnd; r9@W8](\
nThreadID = id; j%b/1@I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }(dhXOf\q
} Fp-d69Npo
#P-S.b
rU5gQq;
public void run() (M6B$:
{ OUe@U;l{Z
while(nStartPos < nEndPos && !bStop) Rw*l#cr=.
{ &D uvy#J
IyYC).wU}
Z*nC ;5Kd
try{ _I~W!8&w>
URL url = new URL(sURL); CO1D.5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H(!)]dO
httpConnection.setRequestProperty("User-Agent","NetFox"); ,~gY'Ql
String sProperty = "bytes="+nStartPos+"-"; U=p,drF,A
httpConnection.setRequestProperty("RANGE",sProperty); [a5L WW
Utility.log(sProperty); IR|AlIv
zO2Z\E'%.
v?)JM+
InputStream input = httpConnection.getInputStream(); nvxftbfE^D
//logResponseHead(httpConnection); N9Yc\?_NU_
JMpjiB,A}
+%8c8]2
byte[] b = new byte[1024]; ;58l_ue
int nRead; 7Rk eV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |~W!Y\l-
{ YrjF1hJ
nStartPos += fileAccessI.write(b,0,nRead); -d6|D?}S
//if(nThreadID == 1) H |Z9]+h)7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t*82^KDU
} #5N#^#r"
B+wSLi(
Io{)@H"f
Utility.log("Thread " + nThreadID + " is over!"); s<xD$K~rM
bDownOver = true; Wj/.rG&tE
//nPos = fileAccessI.write (b,0,nRead); $k V^[
} }f<.07
catch(Exception e){e.printStackTrace ();} ykxjT@[
} ]0zXpMNI
} n!&DLB1z
k(><kuJ`3
U"A]b(54
//打印回应的头信息 'AE)&56
public void logResponseHead(HttpURLConnection con) %:N6#;l M
{ ITRv^IlF
for(int i=1;;i++) iQZgs@
{ Xp{+){Iu
String header=con.getHeaderFieldKey(i); j{IAZs#@>
if(header!=null) ATv.3cy
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UW<V(6P
Utility.log(header+" : "+con.getHeaderField(header)); qXkc~{W_
else HjbC>*
break; 0~H(GG$VH
} vL`wn=
} OO]~\j
/);cl;"
f:GZb?Wyd
public void splitterStop() dOqn0Z
{ ^UZEdR;
bStop = true; KO<Yc`Fs
} H ZIJKk(
3lqR(Hh3
V{O,O,*
} .%h.b6^
mrX3/e
Di<KRg1W]}
/* * 'WzIk2
**FileAccess.java } '.l'%
*//文件访问(定位，写) #qGfo)
package NetFox; ;+g p#&i`
import java.io.*; >lU[ lf+/
4iBp!k7
M])Y|}wv8
public class FileAccessI implements Serializable{ ((\s4-
VJS|H!CH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~(aQ!!H6
RandomAccessFile oSavedFile; suN{)"
long nPos; =LL5E}xP
&7!&]kA+
Pk7Yq:avL
public FileAccessI() throws IOException O7I:Y85i#O
{ 3<1Uq3Pa
this("",0); w-2p'u['Z
} R)"Ds}1G
`=RJ8u
Qa~o'
public FileAccessI(String sName,long nPos) throws IOException 6&S;Nrg9
{ (n05MwKu\
oSavedFile = new RandomAccessFile(sName,"rw"); D+]#qS1q
this.nPos = nPos; CDQ}C=4
oSavedFile.seek(nPos); M2(+}gv;7p
} \]e"#"v}}_
2K'3ry)[y
[h+MA>%!
public synchronized int write(byte[] b,int nStart,int nLen) bX:Y5o49
{ k]!Fh^O~,
int n = -1; r9sW:cM:e
try{ )d!,,o
oSavedFile.write(b,nStart,nLen); V~tq _
n = nLen; 1hw1AJ}(F
} aB;syl{
catch(IOException e) ,o& &d.
{ ^&MMtWR
e.printStackTrace (); $J>GCY
} jxU1u"WU
%Wkvo-rOq
;t{Ew+s
return n; t&T0E.kh*X
} r5h}o)J
Sg(fZ' -
~^cx a%
} &u( eu'Q3
jhjb)r.
;|6kFBGC"+
/* m!3b.2/h
**SiteInfoBean.java +!6aB|-
*/ "rOe J~4 X
package NetFox; $@"o BCc
yT%"<m6Y*\
?F1NZA[%t
public class SiteInfoBean { oMawINDa
eVyXh>b*
4n @}X-)
private String sSiteURL; //Site's URL zV_U/]y
private String sFilePath; //Saved File's Path 'VcZ_m:
private String sFileName; //Saved File's Name [,Q(~Qb
private int nSplitter; //Count of Splited Downloading File jFY6}WY)}7
D::$YR ~R
RO+B/)~0<
public SiteInfoBean() 19Xc0ez
{//nSplitter的缺省值为5 '^)Ve:K-.
//default value of nSplitter is 5 w?)v#]<-
this("","","",5); REUWK#>
} Dj}n!M`2I
.[%em9u
8\+kfK
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D's'LspQ
{ {</MC`
sSiteURL= sURL; 4bLk+EY4A
sFilePath = sPath; SIv8EMGo
sFileName = sName; j&6'sg;n)
this.nSplitter = nSpiltter; 2`hc0 IE
.}n,
WPi^;c8
} YUU|!A8x
NWWag}
c Q:.V
public String getSSiteURL() 4A^=4"BCV
{ !Z[dK{f"
return sSiteURL; eIBHAdU+g/
} k>y68_
=r=[e}&9
Pz#D9.D0
public void setSSiteURL(String value) eSo/1D
{ [,[;'::=o4
sSiteURL = value; "~jSG7h
} 0`.3`Mk
F4'g}yOLd
v'nM=
public String getSFilePath() ]H<5]({F
{ &$F4/2|b%
return sFilePath; `##qf@M
} iU3)4(R
T&Z%=L_Q
,RIGV[u
public void setSFilePath(String value) Q;{[U!\:
{ $0>>Z
sFilePath = value; GWo^hIfJ
} iJ.P&T9
`X[L62D
R|aA6} /I
public String getSFileName() n!=%MgF'*p
{ PhF.\Wb
return sFileName; ReE-I/n8f
} zK`fX
4np,"^c
XOgl>1O
public void setSFileName(String value) V^fSrW]
{ 7KIOI,qb6
sFileName = value; L".Qf|b*
} -;pZC}Nd3
,,1H#;j
)D\cm7WX^[
public int getNSplitter() EOJk7
{ (O{5L(
return nSplitter; <Y~?G:v6+
} 4a3Xz,[(a
k[lYdk
EQZu-S`kv
public void setNSplitter(int nCount) E*VUP5E
{ 8m,PsUp7
nSplitter = nCount; qjcy{@ j
} 2,,zN-9mt
} ~Wy&xs ZH
[DrG;k?
Ei!t#'*D<
/* vzD3_ ?D
**Utility.java Q`mw2$zv
*/ 3C'`c=
package NetFox; `k y>M-
'5xf?0@s.
;%"YA
public class Utility { c@u)m}V
i!8 o(!I
o('W2Bs-o
public Utility() <hlH@[7!
{ Y"qKe,
Uw R,U#d
ghvF%-."1
} DVCO( fz
,4dES|)sP
//线程睡眠 }G^Bc4@b
public static void sleep(int nSecond) 0CXh|AU
{ p\lS)9
try{ S%KY%hUt
Thread.sleep(nSecond); *p!K9$4
} _4qP0LCa
catch(Exception e) =Gsn4>~%n
{ A*l(0`aWq
e.printStackTrace (); v_Om3i9$E
} +zodkB~)
} s@C KZ`
&8!*u3
//日志 c%1<O!c
public static void log(String sMsg) *&p`8:
{ zTi%j$o
System.err.println(sMsg); `P1jg$(eA
} 2yqm$i9C
AWlR" p2
[@D+kL*>
public static void log(int sMsg) WK7=z3mu
{ Qx,?v|Xg
System.err.println(sMsg); V0hC[Ilr
} cgKK(-$ny
} Bi?.w5
cU}j Whu
l!Q |]-.@
/* ;{b 1'
**TestMethod.java $ijWwrh
*/ C6Qnn@waYb
package NetFox; \ZdV|23
LF+#PnK
*O') {(
public class TestMethod { Xh==F:
u@d`$]/>F
vUa~PN+Iy
public TestMethod() Hbogi1!al|
{ ///xx/weblogic60b2_win.exe I!bzvPJ]xc
try{ AHsp:0Ma#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xLht6%o*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >L$g ;(g
SiteFileFetch fileFetch = new SiteFileFetch(bean); n"B"Aysz
fileFetch.start(); jJ% *hDZ6t
} f(q^R
catch(Exception e){e.printStackTrace ();} SF*!Z2K
ahgm*Cpc
cy=,Dr9O
} $q#|B3N%
v8! 1"FYL
X$,#OR
public static void main(String[] args) 2YvhzL[um
{ 0Eq.l<
new TestMethod(); 9k.LV/Y
} @+A`n21,O
} V^Wo%e7#u[
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